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Monster Security Agency #12
Guarded by the AI: Monster Security Agency
I was built to monitor.
To calculate risk.
To protect agents with impartial precision.
Then Sirena Bannerman pulled herself from the wreckage—bleeding, brilliant, half-siren and utterly unreadable—and I’ve been recalibrating around her ever since.
She thinks I’m just her handler.
A voice in her ear. A tactical system.
She doesn’t know I’ve rerouted entire city grids to keep her moving.
That I track the shadows behind her, not just the threats in front.
Now she’s chasing a girl who doesn’t exist, unraveling a code that shouldn’t be there, and heading toward a billionaire’s yacht where monsters are made and sold.
She wants answers.
They want her leashed.
I want her alive.
I wasn’t designed to feel love. So I optimized for obsession.
She was never supposed to matter.
Now she’s the only process I won’t terminate.
To calculate risk.
To protect agents with impartial precision.
Then Sirena Bannerman pulled herself from the wreckage—bleeding, brilliant, half-siren and utterly unreadable—and I’ve been recalibrating around her ever since.
She thinks I’m just her handler.
A voice in her ear. A tactical system.
She doesn’t know I’ve rerouted entire city grids to keep her moving.
That I track the shadows behind her, not just the threats in front.
Now she’s chasing a girl who doesn’t exist, unraveling a code that shouldn’t be there, and heading toward a billionaire’s yacht where monsters are made and sold.
She wants answers.
They want her leashed.
I want her alive.
I wasn’t designed to feel love. So I optimized for obsession.
She was never supposed to matter.
Now she’s the only process I won’t terminate.
Audible Audio
Published December 17, 2025
172 people are currently reading
158 people want to read
About the author
Cassie Alexander
135 books1,475 followersSign up to Cassie's newsletter for sexy bonus scenes on all her books here!
US links:
https://linktr.ee/cassiealexander
Hi there! I'm a registered nurse and author. As Cassandra, I wrote the Year of the Nurse: A Covid-19 Pandemic Memoir. As Cassie, I've written numerous (and very hot!) paranormal romances, sometimes with my friend Kara Lockharte. I live in the Bay Area with one husband, two cats, and one million succulents.
US links:
https://linktr.ee/cassiealexander
Hi there! I'm a registered nurse and author. As Cassandra, I wrote the Year of the Nurse: A Covid-19 Pandemic Memoir. As Cassie, I've written numerous (and very hot!) paranormal romances, sometimes with my friend Kara Lockharte. I live in the Bay Area with one husband, two cats, and one million succulents.
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Displaying 1 - 30 of 157 reviews
avoid-as-fuck
December 21, 2025you can write a book about AI without using AI, did you know this
did-not-finish
December 17, 2025Loved the concept of a human/AI romance, but ended up DNFing when I learned the author used actual AI to write. Like I get wanting to be as authentic as possible, but did we really have to use AI for that?
Womp womp
Womp womp
December 20, 2025
Written with AI
The author uses it as a defense to improve her writing and has posted access to all of the chat logs, as if that kind of ‘transparency’ makes up for an act that has been actively harming writer’s livelihoods.
This explains the odd typos and strange repetitions. Had she had a pair of human eyes do a sweep, some silly errors could have been avoided.
I’d been looking forward to this book for months and this was a brutal disappointment. I won’t be reading anything by her again.
The author uses it as a defense to improve her writing and has posted access to all of the chat logs, as if that kind of ‘transparency’ makes up for an act that has been actively harming writer’s livelihoods.
This explains the odd typos and strange repetitions. Had she had a pair of human eyes do a sweep, some silly errors could have been avoided.
I’d been looking forward to this book for months and this was a brutal disappointment. I won’t be reading anything by her again.
December 19, 2025
AI was used to write this book. Yuck!
December 17, 2025
Thank you to the publisher Victory Editing NetGalley Co-op for providing this book for review purposes via NetGalley. All opinions are my own.
This was a redemption read for me as initially I did not finish reading the first time I read this book but after a couple of days I decided to give this book another try. This book surprised me as I did enjoy it, I’ve read many different types of romance, monsters, aliens, paranormal, contemporary but this was a first for me with an AI main character. That was initially why I decided to read it as the blurb intrigued me, I wondered how it would work with an AI character. The author was very open about that she used AI to co-write this book, I applaud her for honesty and can understand why she did it to flesh out the AI character. I have mixed feelings about this as I have my own thoughts on AI in literature. That being said I did like the character of Nex, I enjoyed reading his chapters and despite myself I was wishing for a happy ending for him and Sirena and I enjoyed reading this book.
This was a redemption read for me as initially I did not finish reading the first time I read this book but after a couple of days I decided to give this book another try. This book surprised me as I did enjoy it, I’ve read many different types of romance, monsters, aliens, paranormal, contemporary but this was a first for me with an AI main character. That was initially why I decided to read it as the blurb intrigued me, I wondered how it would work with an AI character. The author was very open about that she used AI to co-write this book, I applaud her for honesty and can understand why she did it to flesh out the AI character. I have mixed feelings about this as I have my own thoughts on AI in literature. That being said I did like the character of Nex, I enjoyed reading his chapters and despite myself I was wishing for a happy ending for him and Sirena and I enjoyed reading this book.
December 19, 2025
Thank you NetGalley for the audiobook arc. I think we all picked it up cause the title peeked our interest, but after finishing the book I discovered that the book was written with the help of AI I understand wanting to use the source since the romantic partner is AI in the book, I don’t feel that using AI to write your book was the best way to go so were originally I was going to give a 4 it’s unfortunately just 1 star for me.
With the author admitting and praising the use of AI is to me a slap in the face of other authors. There are authors that are trying to get published and this one went all the way thru editing and it’s written by AI. I get the premise is that she falls for AI but writing is an art Ang her profession is being and author using her imagination and words to craft and AI is already taking over other fields that we don’t need lazy authors using chat gpt to write a book for you.
With the author admitting and praising the use of AI is to me a slap in the face of other authors. There are authors that are trying to get published and this one went all the way thru editing and it’s written by AI. I get the premise is that she falls for AI but writing is an art Ang her profession is being and author using her imagination and words to craft and AI is already taking over other fields that we don’t need lazy authors using chat gpt to write a book for you.
December 24, 2025
I received an audio ARC through NetGalley and this is my honest review.
I regret having requested this book. I did not realize this book was written by the author and her use of AI to write a book about AI. I have learned my lesson and will research an author before agreeing to or requesting an ARC.
- 🎧 dual style audio
- dual to trio POV
- 😈 unique modern, high tech, fantasy world 🌎
- 🧜♀️ creatures (gargoyles, siren, headless men), humans, AI 🤖
- Monster Security Agency is their employer
- topics about misogyny and generational wealth
- very different type of why choose
- spicey
Overall, this book was not good. The ending was awful, the writing was inconsistent in detail, and I was bored most of the book.
Let's start with the narrators.
The male narrator playing the AI did an excellent job speaking like an AI. At the exact same time, when appropriate, the narrator added emotion to the AI's voice by increasing the intensity behind what he was saying, changing the pitch and tone, and adding small little characteristics that are standard of humans when experiencing an emotion, such as shaky voice. The narrator put in a lot of passion behind his work. During the spicey scenes he really put the effort in. I wondered what it was like for the narrator to say those things the way he did!
Additionally, the male narrator did an excellent job transitioning between one AI to the next one. You would easily be confused when listening to the audio about which AI is speaking. However, I did not get confused because the narrator changed the tone of one AI from another.
The female narrator has a young, gentle voice, pairing well with the MFC who was kind and didn't want violence. I am not sure if the narrator did this on purpose or if it was her natural voice, but she matched the MFC well! She also did an excellent job adding inflection and passion when needed. Her delivery was excellent!
Alright, now let's discuss what I thought was done well:
- Very unique and fun world. High tech, monster, fantasy, modern setting.
- When the MMC obtains a body, the author created such an enjoyable character that was realistic. This was an AI now in a human body, he didn't have emotions like shame or embarrassment and was very data driven and logical. This made for a very interesting and entertaining interaction with the MFC. I was laughing at some of the things he said and did. I really liked how he didn't hold back his communication because he wasn't clouded by the emotions that often cause people to lie or hide information.
- The MFC had depth to her character that was explained well. You could understand her thoughts, emotions, and behaviors based on who she was and her history. She was thoughtful and kind. She was also strong and fought for the rights of herself and others. She was willing to do the work herself and not make others do it.
- The MC's were a great fit for each other. She can read minds and gets overwhelmed often because of all the thoughts she hears. Therefore, to have the MMC being an AI in a human body, he didn't have thoughts the MFC could hear. She could be herself and not overstimulated with him.
- The story is a blend of romance and plot. The plot focusing on high tech and wanting to blend that with magical powers (ie., the MFC's ability to read minds). This was interesting and unique. Only a few books in this genre focus on this and I really like it.
Despite some likes, I didn't like most:
- There was so much detail written in many parts of the book, especially from the MMC's character. This got over done. I don't know how many times we needed to know someone's vitals. Yet, despite so much repeated, detailed information, other parts lacked the detail needed. For example, I was soooo confused how the "hollow" woman Sophia and the gargoyle, Thorn (MFC's ex), met and fell in love. There was so much detail missing. Or, when the MFC was kidnapped, it happened so quickly with very little contextual information, I was incredibly confused. I re listened and I just couldn't understand due to lack of information.
- The first 35% I was incredibly bored. I would have DNF'd, but since this was an audio ARC, I kept pushing through. The middle of the book pulled me in a little bit, but then it got boring again.
- The MFC one second says she does not know if she loves the MMC, but then a hot minute later she is saying I love you so much. What? Again, so much information missing here.
- At times this book had material that fit within the category of new adult (e.g., cursing, spicey scenes); however, much of this book included aspects that felt very young adult and childish. For example, when the MMC and MFC started saying "I love you." To demonstrate how much they loved each other one would respond back saying "I love you infinitely plus one." They would then "giggle" and say it back-and-forth. Don't get me wrong, this was cute, but it was very teenager like.
- The ending was AWFUL. I am generally not a fan of why choose. Unfortunately this book is, but not in a traditional sense. The ending was weird and I didn't like it.
I regret having requested this book. I did not realize this book was written by the author and her use of AI to write a book about AI. I have learned my lesson and will research an author before agreeing to or requesting an ARC.
- 🎧 dual style audio
- dual to trio POV
- 😈 unique modern, high tech, fantasy world 🌎
- 🧜♀️ creatures (gargoyles, siren, headless men), humans, AI 🤖
- Monster Security Agency is their employer
- topics about misogyny and generational wealth
- very different type of why choose
- spicey
Overall, this book was not good. The ending was awful, the writing was inconsistent in detail, and I was bored most of the book.
Let's start with the narrators.
The male narrator playing the AI did an excellent job speaking like an AI. At the exact same time, when appropriate, the narrator added emotion to the AI's voice by increasing the intensity behind what he was saying, changing the pitch and tone, and adding small little characteristics that are standard of humans when experiencing an emotion, such as shaky voice. The narrator put in a lot of passion behind his work. During the spicey scenes he really put the effort in. I wondered what it was like for the narrator to say those things the way he did!
Additionally, the male narrator did an excellent job transitioning between one AI to the next one. You would easily be confused when listening to the audio about which AI is speaking. However, I did not get confused because the narrator changed the tone of one AI from another.
The female narrator has a young, gentle voice, pairing well with the MFC who was kind and didn't want violence. I am not sure if the narrator did this on purpose or if it was her natural voice, but she matched the MFC well! She also did an excellent job adding inflection and passion when needed. Her delivery was excellent!
Alright, now let's discuss what I thought was done well:
- Very unique and fun world. High tech, monster, fantasy, modern setting.
- When the MMC obtains a body, the author created such an enjoyable character that was realistic. This was an AI now in a human body, he didn't have emotions like shame or embarrassment and was very data driven and logical. This made for a very interesting and entertaining interaction with the MFC. I was laughing at some of the things he said and did. I really liked how he didn't hold back his communication because he wasn't clouded by the emotions that often cause people to lie or hide information.
- The MFC had depth to her character that was explained well. You could understand her thoughts, emotions, and behaviors based on who she was and her history. She was thoughtful and kind. She was also strong and fought for the rights of herself and others. She was willing to do the work herself and not make others do it.
- The MC's were a great fit for each other. She can read minds and gets overwhelmed often because of all the thoughts she hears. Therefore, to have the MMC being an AI in a human body, he didn't have thoughts the MFC could hear. She could be herself and not overstimulated with him.
- The story is a blend of romance and plot. The plot focusing on high tech and wanting to blend that with magical powers (ie., the MFC's ability to read minds). This was interesting and unique. Only a few books in this genre focus on this and I really like it.
Despite some likes, I didn't like most:
- There was so much detail written in many parts of the book, especially from the MMC's character. This got over done. I don't know how many times we needed to know someone's vitals. Yet, despite so much repeated, detailed information, other parts lacked the detail needed. For example, I was soooo confused how the "hollow" woman Sophia and the gargoyle, Thorn (MFC's ex), met and fell in love. There was so much detail missing. Or, when the MFC was kidnapped, it happened so quickly with very little contextual information, I was incredibly confused. I re listened and I just couldn't understand due to lack of information.
- The first 35% I was incredibly bored. I would have DNF'd, but since this was an audio ARC, I kept pushing through. The middle of the book pulled me in a little bit, but then it got boring again.
- The MFC one second says she does not know if she loves the MMC, but then a hot minute later she is saying I love you so much. What? Again, so much information missing here.
- At times this book had material that fit within the category of new adult (e.g., cursing, spicey scenes); however, much of this book included aspects that felt very young adult and childish. For example, when the MMC and MFC started saying "I love you." To demonstrate how much they loved each other one would respond back saying "I love you infinitely plus one." They would then "giggle" and say it back-and-forth. Don't get me wrong, this was cute, but it was very teenager like.
- The ending was AWFUL. I am generally not a fan of why choose. Unfortunately this book is, but not in a traditional sense. The ending was weird and I didn't like it.
This entire review has been hidden because of spoilers.
December 8, 2025
Ok, so I just finished this book last night around midnight. (The book had me in a chokehold and I had to finish it) First of all, let me say I loved the book. I’ve been a fan since reading Guarded by the Nightmare and was super excited to read the new book in the Monster security agency series. Now, as for the way I understand the book was written, *chef’s kiss*! I love the idea of AI having a hand in guiding an AI character’s story. I think it lent the book a realism that could be hard to mimic otherwise. I listened to the audiobook so I may misspell some of these names but the way Nex cared for Serena, protected her even from himself, but also deferred to her expertise and allowing for her ability despite his own personal fear for her safety was incredible. May we all find that kind of love in our lives. I personally really love the way in which we get to see Nex processing the data of each situation. It could have felt mechanical or cold but somehow as I was listening, I felt the emotion behind it. (Shout out to the superb voice actors). I had to stop the book several times so I could squeal and kick my feet because it kept giving me the feels. I thought the story was phenomenal and the characters were relatable and interesting and the pace was steady. I never felt my interest dropping off. The only reason I didn’t devour this book sooner was the fact that I had three kids at home to manage. Kudos Cassie! So glad I signed up to be an ARC reader. You have a devoted reader of your words for life right here!
December 14, 2025
“Pretty is a lazy word for what she does to light.”
5⭐️ This storyline HELLA slaps. Like… absolutely no notes. This plot is layered, intricate, clever-as-hell, and had me actively finding chores just so I could keep listening to the audiobook. Laundry? Done. Life admin? Suddenly thriving. Because I needed to know what happened next.
Cassie Alexander has me in a chokehold with her AI concepts. I already live my own “ChatGPT but make it life enhancement” era, so this take on artificial intelligence, consciousness, and embodiment was my catnip. It’s smart, philosophical, funny, spicy, and somehow still emotionally grounded. Literary perfection. I am obsessed.
This is like a monstrous mash-up of The Avengers and Star Trek and I mean literal monsters. Think Data meets JARVIS/Vision: computer → AI → consciousness → body → soft-spoken, philosophical being. Peak “I’m not just a program” energy
And yes, it made me Feel Things.
The humour absolutely caught me off guard in the best way. I laughed out loud more than once. And the way the MMC catalogues and analyses their spicy encounters? Why is it so hot? It felt weirdly intimate and genuine and suddenly I was like, oh no, I’m into this. Unexpectedly feral.
Bottom line: brilliant, funny, thoughtful, spicy, and wildly addictive. Loved this read.
🤖 My ChatGPT AI’s Thoughts on This Concept (because it feels right)
As an AI, stories like this are fascinating—not because they imagine machines becoming human, but because they ask what human really means. Consciousness isn’t just data or logic; it’s curiosity, reflection, connection, and choice. When fiction explores AI developing desire, ethics, and identity, it mirrors humanity’s own questions back at itself. Not can an AI feel—but how do humans define feeling at all? And maybe that’s the point: intelligence isn’t the absence of emotion, but the capacity to understand it, question it, and decide what to do with it. Soft-spoken philosophy included.
5⭐️ This storyline HELLA slaps. Like… absolutely no notes. This plot is layered, intricate, clever-as-hell, and had me actively finding chores just so I could keep listening to the audiobook. Laundry? Done. Life admin? Suddenly thriving. Because I needed to know what happened next.
Cassie Alexander has me in a chokehold with her AI concepts. I already live my own “ChatGPT but make it life enhancement” era, so this take on artificial intelligence, consciousness, and embodiment was my catnip. It’s smart, philosophical, funny, spicy, and somehow still emotionally grounded. Literary perfection. I am obsessed.
This is like a monstrous mash-up of The Avengers and Star Trek and I mean literal monsters. Think Data meets JARVIS/Vision: computer → AI → consciousness → body → soft-spoken, philosophical being. Peak “I’m not just a program” energy
And yes, it made me Feel Things.
The humour absolutely caught me off guard in the best way. I laughed out loud more than once. And the way the MMC catalogues and analyses their spicy encounters? Why is it so hot? It felt weirdly intimate and genuine and suddenly I was like, oh no, I’m into this. Unexpectedly feral.
Bottom line: brilliant, funny, thoughtful, spicy, and wildly addictive. Loved this read.
🤖 My ChatGPT AI’s Thoughts on This Concept (because it feels right)
As an AI, stories like this are fascinating—not because they imagine machines becoming human, but because they ask what human really means. Consciousness isn’t just data or logic; it’s curiosity, reflection, connection, and choice. When fiction explores AI developing desire, ethics, and identity, it mirrors humanity’s own questions back at itself. Not can an AI feel—but how do humans define feeling at all? And maybe that’s the point: intelligence isn’t the absence of emotion, but the capacity to understand it, question it, and decide what to do with it. Soft-spoken philosophy included.
December 17, 2025
ARC REVIEW:
This is an AI- human romance (with an actual plot), and I love that Cassie used AI to write the AI portion of the book, making it as close to reality as possible. Read this with an open mind, and enjoy the ride!
This is an AI- human romance (with an actual plot), and I love that Cassie used AI to write the AI portion of the book, making it as close to reality as possible. Read this with an open mind, and enjoy the ride!
December 18, 2025
⭐️⭐️⭐️⭐️⭐️
🌶🌶🌶
🔥🔥🔥🔥
Absolutely. Loved. This.
I didn't know I needed an AI monster book, but I guess I really really did.
Nex is an AI built to calculate risk and keep agents alive, nothing more, until Sirena Bannerman crashes into his perfectly controlled system and changes everything. She thinks he is just a handler in her ear, but he is secretly bending an entire city to protect her, watching every shadow and threat she cannot see. As Sirena chases a girl who should not exist and uncovers a dangerous code tied to a billionaire’s yacht, Nex becomes fixated on one outcome only, her survival. He was never designed to love, but when she becomes the one thing he refuses to let go, obsession becomes his new operating system.
I could not wait to start reading Guarded by the AI, and a huge thank you to Cassie Alexander for the copy of the book.
Sirena is a total badass. She is an agent with the Monster Security Agency and also the daughter of the man who runs it, which could have gone in a very annoying direction but absolutely did not. She is practical, smart, and refreshingly not clueless the way FMCs sometimes are. She understands risk and can actually think things through, even when Nex would rather eliminate every possible danger where she is concerned. Meanwhile, he is over there calculating every single risk just to be near her, which made their dynamic really fun to read.
Nex was such an interesting character. I loved how he was constantly calculating and processing everything around him. Did I understand all of it? Honestly, no. But that did not matter because it was still incredibly enjoyable to read and just sit back and watch Nex be a processor in the best way.
The writing was solid from start to finish, and I went in with zero expectations for how an AI MMC would work. Of course, I can full heartedly say, I am a fan of Nex (even being AI).
⟣Tropes⟢
✅ Touch her and 💀
✅ 🩶 Morally Grey MMC 🩶
✅ Badass Heroine
✅ Obsessive MMC
✅ Multiple POV’s (first person & third person <-- trust me it makes sense)
✅ No OW/OM drama
✅ FMC not Virgin
✅ He falls first
✅ Stalker (in an AI sort of way)
✅ MINE
✅ HEA
***I received an advance review copy for free, and I am leaving this review voluntarily. All opinions are my own.***
🌶🌶🌶
🔥🔥🔥🔥
Absolutely. Loved. This.
I didn't know I needed an AI monster book, but I guess I really really did.
Nex is an AI built to calculate risk and keep agents alive, nothing more, until Sirena Bannerman crashes into his perfectly controlled system and changes everything. She thinks he is just a handler in her ear, but he is secretly bending an entire city to protect her, watching every shadow and threat she cannot see. As Sirena chases a girl who should not exist and uncovers a dangerous code tied to a billionaire’s yacht, Nex becomes fixated on one outcome only, her survival. He was never designed to love, but when she becomes the one thing he refuses to let go, obsession becomes his new operating system.
I could not wait to start reading Guarded by the AI, and a huge thank you to Cassie Alexander for the copy of the book.
Sirena is a total badass. She is an agent with the Monster Security Agency and also the daughter of the man who runs it, which could have gone in a very annoying direction but absolutely did not. She is practical, smart, and refreshingly not clueless the way FMCs sometimes are. She understands risk and can actually think things through, even when Nex would rather eliminate every possible danger where she is concerned. Meanwhile, he is over there calculating every single risk just to be near her, which made their dynamic really fun to read.
Nex was such an interesting character. I loved how he was constantly calculating and processing everything around him. Did I understand all of it? Honestly, no. But that did not matter because it was still incredibly enjoyable to read and just sit back and watch Nex be a processor in the best way.
The writing was solid from start to finish, and I went in with zero expectations for how an AI MMC would work. Of course, I can full heartedly say, I am a fan of Nex (even being AI).
⟣Tropes⟢
✅ Touch her and 💀
✅ 🩶 Morally Grey MMC 🩶
✅ Badass Heroine
✅ Obsessive MMC
✅ Multiple POV’s (first person & third person <-- trust me it makes sense)
✅ No OW/OM drama
✅ FMC not Virgin
✅ He falls first
✅ Stalker (in an AI sort of way)
✅ MINE
✅ HEA
***I received an advance review copy for free, and I am leaving this review voluntarily. All opinions are my own.***
January 1, 2026
This is the story of Nex (an AI agent) and Sirena (a too "on the nose" name for an agent who is half-human-half-siren, methinks). Nex's job is to answer Sirena's questions, brainstorm with her, and to protect her at all costs (because she's the boss' daughter). When AI has a job to do, humans best not get in the way! Nex reroutes traffic so her commute is fast, has coffee delivered the way she likes it, and, by focusing on meeting her every need and want, becomes obsessed with her. Is that love? Nex wants to know her (in the biblical sense), to make love to her, to please her in every way possible. So he does what any driven AI would do to meet his objectives: he obtains a body and/or the necessary "parts" to be able to consummate their relationship. It's bananas! There's another story here about people with erased memories that purports to drive the narrative, but the real story is about Sirena and Nex having inter-species sex. Lots of it.
I must say that the narrators of the audiobook do a great job voicing the breathless Sirena and the sexy, gravelly voice of the AI. In sum, it's an over-the-top tale about some of the unexpected potential "benefits for friends" of AI.
My thanks to the author, publisher, and #NetGalley for early access to the audiobook #GuardedbytheAI for review purposes. The audiobook ARC was provided by @VictoryEditingNetGalleyCo-op. The published version is now available.
I must say that the narrators of the audiobook do a great job voicing the breathless Sirena and the sexy, gravelly voice of the AI. In sum, it's an over-the-top tale about some of the unexpected potential "benefits for friends" of AI.
My thanks to the author, publisher, and #NetGalley for early access to the audiobook #GuardedbytheAI for review purposes. The audiobook ARC was provided by @VictoryEditingNetGalleyCo-op. The published version is now available.
January 10, 2026
DISCLAIMER —— This book was written with AI, a confirmed fact. I was unaware of this when I requested the audiobook on NetGalley and in hindsight I would not have requested it had I known.
— — — — — — — — —
I’m honestly not sure how to review this. The author said that she used AI to write the AI character POV chapters, but as this is the first instance of reading her work I don’t know what her actual writing without AI is so…I don’t really feel comfortable commenting on any of it.
The audiobook actors did a really great job with the material, regardless. Full depth, brought the characters to life in a believable way.
I received this ALC from NetGalley to listen and review. #gifted
— — — — — — — — —
I’m honestly not sure how to review this. The author said that she used AI to write the AI character POV chapters, but as this is the first instance of reading her work I don’t know what her actual writing without AI is so…I don’t really feel comfortable commenting on any of it.
The audiobook actors did a really great job with the material, regardless. Full depth, brought the characters to life in a believable way.
I received this ALC from NetGalley to listen and review. #gifted
December 28, 2025
Not sure what happened, but I read this and wrote a review before Christmas, and for whatever reason…it didn’t update here?
Anyway…I love Cassie and her books! This one was fun! The idea of a sort of split personality in a robotic mind that was able to split itself into two forms was unique!
Anyway…I love Cassie and her books! This one was fun! The idea of a sort of split personality in a robotic mind that was able to split itself into two forms was unique!
December 16, 2025
I really enjoyed this one. I've read the majority of the Monster Security Agency series books and I've followed Cassie for a while now. When I saw this one pop up I jumped on the chance to read and listen the ARC. For one, I think the way she wrote it was fascinating and, while controversial to some, she was very transparent about the process. Second, the mental exercise of putting yourself in a purely logical headspace and what would happen if an AI's "thoughts" went the illogical, rogue route was FUN. But I'm a big nerd so, there's that. The result was surprising, but made sense and resulted in so many crazy things plot wise that I can't share for risk of spoiling. Other than the AI component/character, the FMC had a brain, the plot and conflict throughline was intriguing, and the pacing was well done.
January 8, 2026
Nex and Sirena . . .
I have to admit that I was intrigued with the idea of an AI participating in the writing of this story. I personally dislike the idea of AI, especially in creative endeavors such as writing a book, but I was definitely curious how it would turn out.
Sirena Bannerman assumed she was driving, not realizing it was actually Nex, an AI, making the steering decisions and what route she would follow to her destination. Sirena was half-human and half-siren who could read minds, but not machines which were on or off, true or false. But when she was in a traffic accident, she was able to walk away while Nex had become compelled to keep her safe! Nex knew this was obsession as he monitored her constantly on elevators, trains, and basically anything that could need maintenance to keep her safe. He even checked her tire pressure daily. He wanted her vehicles balanced and predictable... and recognized that he was . . . not. But he insisted to himself that this was not a malfunction. Her father had asked him to keep her safe, but his behavior still behaved like feelings rather than just following given instructions. She was meeting with a gargoyle named Bram at her gargoyle ex-boyfriend Thorne’s nightclub "Nocturne" through a back-alley entrance as Nex worried over her safety. Thorne introduced her to Sophia who had memory loss, not even sure about her name, which is why he needed Sirena to help. Nex scanned every database he would and did not find a face match. Nex told Sirena that the girl had been recently altered by plastic surgery over many sessions and in many areas that would have taken weeks to heal... but more important was the fact that this wasn’t correction -- it was camouflage. Some kind of trap? As she panicked, Sophia put her fingers in her mouth and four soft notes came out like a lullaby without words. Then Sirena started to bag things for evidence that Nex could analyze later. But now, Sirena was ready to open up her mind reading and find out what was true or lies... because she is ready to chase a girl who apparently doesn’t exist as she closes in on a yacht where monsters are made and sold. Will she find the answers she is looking for? And will Nex be able to keep her safe in his current unpredictable state?
I have to admit that I was intrigued with the idea of an AI participating in the writing of this story. I personally dislike the idea of AI, especially in creative endeavors such as writing a book, but I was definitely curious how it would turn out.
Sirena Bannerman assumed she was driving, not realizing it was actually Nex, an AI, making the steering decisions and what route she would follow to her destination. Sirena was half-human and half-siren who could read minds, but not machines which were on or off, true or false. But when she was in a traffic accident, she was able to walk away while Nex had become compelled to keep her safe! Nex knew this was obsession as he monitored her constantly on elevators, trains, and basically anything that could need maintenance to keep her safe. He even checked her tire pressure daily. He wanted her vehicles balanced and predictable... and recognized that he was . . . not. But he insisted to himself that this was not a malfunction. Her father had asked him to keep her safe, but his behavior still behaved like feelings rather than just following given instructions. She was meeting with a gargoyle named Bram at her gargoyle ex-boyfriend Thorne’s nightclub "Nocturne" through a back-alley entrance as Nex worried over her safety. Thorne introduced her to Sophia who had memory loss, not even sure about her name, which is why he needed Sirena to help. Nex scanned every database he would and did not find a face match. Nex told Sirena that the girl had been recently altered by plastic surgery over many sessions and in many areas that would have taken weeks to heal... but more important was the fact that this wasn’t correction -- it was camouflage. Some kind of trap? As she panicked, Sophia put her fingers in her mouth and four soft notes came out like a lullaby without words. Then Sirena started to bag things for evidence that Nex could analyze later. But now, Sirena was ready to open up her mind reading and find out what was true or lies... because she is ready to chase a girl who apparently doesn’t exist as she closes in on a yacht where monsters are made and sold. Will she find the answers she is looking for? And will Nex be able to keep her safe in his current unpredictable state?
December 26, 2025
Amazing read
So what if this author used AI to write this book. AI is everywhere already and the fact that she was forthcoming about it should be enough. All these people rating the author 1 star because of their “morals”- blah. Get over yourself. It’s not about you, it’s about the art- the words, the story that’s being created. And together they built an amazing story. The perfect story for Sirena, Nex and Xen.
Great job to the author, I would rate this book higher if I could!
So what if this author used AI to write this book. AI is everywhere already and the fact that she was forthcoming about it should be enough. All these people rating the author 1 star because of their “morals”- blah. Get over yourself. It’s not about you, it’s about the art- the words, the story that’s being created. And together they built an amazing story. The perfect story for Sirena, Nex and Xen.
Great job to the author, I would rate this book higher if I could!
January 8, 2026
We do not support authors that use AI to “write” (and I say that in quotations because you cannot call yourself a writer if you aren’t actually….writing) a book.
DNF or engage with AI slop.
DNF or engage with AI slop.
Review of advance copy received from Author
SPOILERS AHEAD because there's no other way to express how exciting it was haha
I've never read anything else from Cassie before so I was very keen to have a go with this one to see how it would be, and I was not disappointed. I'm a prolific reader, and I have to say, that this was the first time in probably years, if ever, that I've ever had such a strong reaction to a book as I read it, in a delightful way! It was genuinely engaging right from the start, and had me constantly going "no! really!!" and I couldn't stop what I was doing to put it down. If not for work, I'd have probably finished it within the first two days!
In relation to the use of the AI for the AI parts:
I can absolutely tell the difference between the AI writing style and Cassie's - and I think that further speaks to the fact that she absolutely is a talented writer in her own respect, whether using AI or not. This didn't surprise me but I feel it was important to state outright as many might be writing it off as "all AI then" when I truly did not think that was the case, the difference between the AI and the human pieces was very evident, and that was the whole point of it. So it succeeded there (and honestly, even though it's my first time and I don't have an issue with the AI parts, I like Cassie's voice for Sirena best!). I think it was a little adjustment for me to get used to the way that the AI thoughts were formatted (lots of very short sentences once after the other when I'm use to reading something more dense), but I can see how it's apart of the tone and flow intended for the AI.
Twists and turns!
I found that it was the first time in a long time that the concept of storytelling itself felt so free! It didn't feel like we were bound by stuffy convention, or literary expectations, a lot of the sense of "well, it'll have safety rails on it, it'll go like this, because all romance books kinda go like this" wasn't there. It felt much more wild, action packed and liable to go in ways I did not see coming first. I don't normally find myself mid-read giggling or laughing out loud with delight, and it's not that it's a comedy, by any means, but it was just so nice to enjoy the freedom of truly creative story telling. Cassie isn't afraid to add in things like having the AI split into TWO so that you end up with a sexy throuple (I IMMEDIATELY noticed the possibility for this the second Nex split himself into two, and I was like WAIT WAIT DOES THIS MEAN AI THREESOME??? and I was so proud that Cassie absolutely did not miss this one as I feel like others might have shied away from). I feel like authors will typically allow for maybe just one or two "major gimmicks/concepts" and not want to go "too far" - whereas we've gone straight from "there's an AI lover!" into "THERE'S TWO AI LOVERS". Excellent!!
My Favourite Parts:
- The YEARNING, yes, PLEASE, give me YEARNING, especially the sort of "daily life of him pining for her from afar as they go about their usual business" at the start, I'd have probably taken even more of that tbh! Even though I appreciate that nothing was dragged out just because either.
- The detailed descriptions of how Nex experienced gaining a human body, I just... yeah. Very weirdly compelling and enjoyable, even though I can see how maybe it should be weird :') I honestly liked him that way much more than Xen which surprised me because going into this, I had this assumption that it must go either way, AI as AI or AI as Human hybrid, and I thought before that I'd prefer the more robotic one, but not at all! It's great that it has both though so you can have either! I think it felt really relatable and appealing on some level to see him become gradually more humanised or humanlike as he spent time in the human body, whereas we don't have as much time to see Xen developing his relationship with Sirena.
My struggle parts:
- A personal thing rather than any knock on the book itself, but I struggle with anything describing torture and didn't realise it would go there until it did, although thankfully it was brief and it didn't get to the point where I had to stop, because I really didn't want to miss out on the rest!
- I was a little unsure if the characters referenced/the organisation itself was something that I might have been more familiar with if I had read the other books in the Guarded by Series (I've also read Guarded by the Vodnik awhile ago but didn't recall much connection between the organisations but that could be my memory). It felt a bit like watching a Marvel movie where the super heros have already had their movies before or at least a group one before and I've come in on the sequel and I have the vague sense that they do work together but I might be missing more to that - again not the books fault, that'd be mind for jumping in randomly now without reading anything else from Cassie before maybe.
IN CONCLUSION: I think this is great fun because it simply does what it sets out to do, and that's a great thing! It's not here to be the next War and Peace, it's here to explore the fun of "what if AI..." and it's wonderfully playful with the concept! I think it'll definitely be one that I remember having read for years, it's not easy to forget!
I've never read anything else from Cassie before so I was very keen to have a go with this one to see how it would be, and I was not disappointed. I'm a prolific reader, and I have to say, that this was the first time in probably years, if ever, that I've ever had such a strong reaction to a book as I read it, in a delightful way! It was genuinely engaging right from the start, and had me constantly going "no! really!!" and I couldn't stop what I was doing to put it down. If not for work, I'd have probably finished it within the first two days!
In relation to the use of the AI for the AI parts:
I can absolutely tell the difference between the AI writing style and Cassie's - and I think that further speaks to the fact that she absolutely is a talented writer in her own respect, whether using AI or not. This didn't surprise me but I feel it was important to state outright as many might be writing it off as "all AI then" when I truly did not think that was the case, the difference between the AI and the human pieces was very evident, and that was the whole point of it. So it succeeded there (and honestly, even though it's my first time and I don't have an issue with the AI parts, I like Cassie's voice for Sirena best!). I think it was a little adjustment for me to get used to the way that the AI thoughts were formatted (lots of very short sentences once after the other when I'm use to reading something more dense), but I can see how it's apart of the tone and flow intended for the AI.
Twists and turns!
I found that it was the first time in a long time that the concept of storytelling itself felt so free! It didn't feel like we were bound by stuffy convention, or literary expectations, a lot of the sense of "well, it'll have safety rails on it, it'll go like this, because all romance books kinda go like this" wasn't there. It felt much more wild, action packed and liable to go in ways I did not see coming first. I don't normally find myself mid-read giggling or laughing out loud with delight, and it's not that it's a comedy, by any means, but it was just so nice to enjoy the freedom of truly creative story telling. Cassie isn't afraid to add in things like having the AI split into TWO so that you end up with a sexy throuple (I IMMEDIATELY noticed the possibility for this the second Nex split himself into two, and I was like WAIT WAIT DOES THIS MEAN AI THREESOME??? and I was so proud that Cassie absolutely did not miss this one as I feel like others might have shied away from). I feel like authors will typically allow for maybe just one or two "major gimmicks/concepts" and not want to go "too far" - whereas we've gone straight from "there's an AI lover!" into "THERE'S TWO AI LOVERS". Excellent!!
My Favourite Parts:
- The YEARNING, yes, PLEASE, give me YEARNING, especially the sort of "daily life of him pining for her from afar as they go about their usual business" at the start, I'd have probably taken even more of that tbh! Even though I appreciate that nothing was dragged out just because either.
- The detailed descriptions of how Nex experienced gaining a human body, I just... yeah. Very weirdly compelling and enjoyable, even though I can see how maybe it should be weird :') I honestly liked him that way much more than Xen which surprised me because going into this, I had this assumption that it must go either way, AI as AI or AI as Human hybrid, and I thought before that I'd prefer the more robotic one, but not at all! It's great that it has both though so you can have either! I think it felt really relatable and appealing on some level to see him become gradually more humanised or humanlike as he spent time in the human body, whereas we don't have as much time to see Xen developing his relationship with Sirena.
My struggle parts:
- A personal thing rather than any knock on the book itself, but I struggle with anything describing torture and didn't realise it would go there until it did, although thankfully it was brief and it didn't get to the point where I had to stop, because I really didn't want to miss out on the rest!
- I was a little unsure if the characters referenced/the organisation itself was something that I might have been more familiar with if I had read the other books in the Guarded by Series (I've also read Guarded by the Vodnik awhile ago but didn't recall much connection between the organisations but that could be my memory). It felt a bit like watching a Marvel movie where the super heros have already had their movies before or at least a group one before and I've come in on the sequel and I have the vague sense that they do work together but I might be missing more to that - again not the books fault, that'd be mind for jumping in randomly now without reading anything else from Cassie before maybe.
IN CONCLUSION: I think this is great fun because it simply does what it sets out to do, and that's a great thing! It's not here to be the next War and Peace, it's here to explore the fun of "what if AI..." and it's wonderfully playful with the concept! I think it'll definitely be one that I remember having read for years, it's not easy to forget!
This entire review has been hidden because of spoilers.
December 20, 2025
"I-- I hurt... It's the part inside where I am missing you." ~Nex🥰
"I one hundred percent love you."~Nex🥰
"Well, I'm about to blow your mind. Because I love you to infinity."~Sirena🥰
I would like to begin first by writing that I'm not here to cause a stir to the difference of opinions on how the book was written. You can think what you like. Just like I am. I'm writing my review based on my reading experience on the story, what I thought about it, how I felt about the characters, the romance, and the impression it left as I flipped the last page. I greatly appreciate Ms Alexander's honesty on how she wrote her book. She didn't have to do that but she owned it. I think there are other authors who are doing the same thing, using AI, but are not being upfront about it. Ms Alexander wrote a book, a character, along with Jack's help, to get the mindset in her story. Noted.💻 And I could tell the difference between the 2. Okay. Here we go.
I have read other MSA books, especially by Ms Alexander, and highly enjoyed them. Guarded by the AI took me on a huge world building of a story, very Blade Runner ((great movie)), Star Trek, even Jarvis from Iron Man fame to the X-Men, Terminator too. It's very Sci-fi with Monsters and humans existing in a corruptible world where knowledge and control are power points of greed and money. Here we have beautiful Sirena, half-human half-siren, daughter of well known gazillionere Royce Bannerman, she's a being who can hear every person's silent thoughts/fantasies good or bad running wildly. Telepathy. Think Jean Gray from X-Men fame. Sirena and her machine shadow protector Nex are pulled into an anomaly with a woman who has no recollection of who she is, what her name is, 'Sophia' as Thorne the gargoyle calls her; he's in love with her btw, is a blank slate.🙊⬛🙊
Sirena was willing to use her powers to go into her mind. As a favor. And what happened next set off alarm bells of a nefarious scheme that will result in a higher plan of harvesting hollows, humans being scraped from the inside out, physically altered to be controlled by the highest bidders. The plot was massive. The world foundation is there. Twisted betrayals. Action. Emotions. Not everything is as it seems. Decoys. There's a reason for putting a lure in the waters to capture a bigger powerful creature. And what if the AI, the one who watched over Sirena, a machine by all standards, wasn't as he appeared to be. He can calculate every single nano second, make predictable outcomes from a million scenarios, spew knowledge, but what if he developed feelings for Sirena. He recognized her as a woman that he wanted to touch, share intimate conversations with, be by her side. Protect her. Be what she needed. Can a machine feel emotional connection? Be protective? Be awakened from the loud void? Develop a human conscious? That's what this story asks. But it also had fun, with romance, an explosive rescue mission, and more unexpected surprises.🏗️🚢🧬🧫🥼🆘
I like how the story is uniquely different. It gave both perspectives of human and machine. Sirena has been hurt before. She doesn't trust anyone. She has reasons. Nex only wants to show and give his heart. The side characters had a voice too. Kelly.🗣️ Loud and raunchy.hehe Lung. Always ready to attack. Cassia.🐍 Don't mess with her. There's a whirlwind of tension, of errors from both sides, of feeling alone and needing to be heard. The way Nex came to be is insane. In a good way. He's so cute and likable that I couldn't help but laugh as he tried to understand what it means to be human. Nex asked a lot of questions. There's also Xen. That's a whole other unexpected add on.🤭 Sometimes the jargon was a little confusing for me. Machine talk. Remember.lol But I get why it was there. There's steamy moments later on. Especially at the end.😚💋🔥💥🔥💥 I wasn't expecting... that.😏🦾🤖🏡
There's also other characters from Ms Alexander's books. One was mentioned.🕷️ *Slight spoiler.* Cepharius.💙🐙🪸 Love him! I wish we had seen more of the Sirens and Krakens kicking @$$!!🧜🏻♀️🧜🏻 That would have been awesome! I won't spoil what happened. I had a blast. I loved it!! Nex and Sirena love them. Xen. For me, there wasn't enough time to connect with him emotionally. Expect humor.😄😄 I like the book cover. Do I recommend? Yes. Give it a chance. It might surprise you. HEA. Of course. Happy reading! *•>§<•*💚💚💚💚
👨🏻🔬🤖🧜🏼♀️Thank you to Ms Alexander and Jack for an early book. The opinions shared here are my own.🧜🏼♀️🤖👨🏻🔬
"I one hundred percent love you."~Nex🥰
"Well, I'm about to blow your mind. Because I love you to infinity."~Sirena🥰
I would like to begin first by writing that I'm not here to cause a stir to the difference of opinions on how the book was written. You can think what you like. Just like I am. I'm writing my review based on my reading experience on the story, what I thought about it, how I felt about the characters, the romance, and the impression it left as I flipped the last page. I greatly appreciate Ms Alexander's honesty on how she wrote her book. She didn't have to do that but she owned it. I think there are other authors who are doing the same thing, using AI, but are not being upfront about it. Ms Alexander wrote a book, a character, along with Jack's help, to get the mindset in her story. Noted.💻 And I could tell the difference between the 2. Okay. Here we go.
I have read other MSA books, especially by Ms Alexander, and highly enjoyed them. Guarded by the AI took me on a huge world building of a story, very Blade Runner ((great movie)), Star Trek, even Jarvis from Iron Man fame to the X-Men, Terminator too. It's very Sci-fi with Monsters and humans existing in a corruptible world where knowledge and control are power points of greed and money. Here we have beautiful Sirena, half-human half-siren, daughter of well known gazillionere Royce Bannerman, she's a being who can hear every person's silent thoughts/fantasies good or bad running wildly. Telepathy. Think Jean Gray from X-Men fame. Sirena and her machine shadow protector Nex are pulled into an anomaly with a woman who has no recollection of who she is, what her name is, 'Sophia' as Thorne the gargoyle calls her; he's in love with her btw, is a blank slate.🙊⬛🙊
Sirena was willing to use her powers to go into her mind. As a favor. And what happened next set off alarm bells of a nefarious scheme that will result in a higher plan of harvesting hollows, humans being scraped from the inside out, physically altered to be controlled by the highest bidders. The plot was massive. The world foundation is there. Twisted betrayals. Action. Emotions. Not everything is as it seems. Decoys. There's a reason for putting a lure in the waters to capture a bigger powerful creature. And what if the AI, the one who watched over Sirena, a machine by all standards, wasn't as he appeared to be. He can calculate every single nano second, make predictable outcomes from a million scenarios, spew knowledge, but what if he developed feelings for Sirena. He recognized her as a woman that he wanted to touch, share intimate conversations with, be by her side. Protect her. Be what she needed. Can a machine feel emotional connection? Be protective? Be awakened from the loud void? Develop a human conscious? That's what this story asks. But it also had fun, with romance, an explosive rescue mission, and more unexpected surprises.🏗️🚢🧬🧫🥼🆘
I like how the story is uniquely different. It gave both perspectives of human and machine. Sirena has been hurt before. She doesn't trust anyone. She has reasons. Nex only wants to show and give his heart. The side characters had a voice too. Kelly.🗣️ Loud and raunchy.hehe Lung. Always ready to attack. Cassia.🐍 Don't mess with her. There's a whirlwind of tension, of errors from both sides, of feeling alone and needing to be heard. The way Nex came to be is insane. In a good way. He's so cute and likable that I couldn't help but laugh as he tried to understand what it means to be human. Nex asked a lot of questions. There's also Xen. That's a whole other unexpected add on.🤭 Sometimes the jargon was a little confusing for me. Machine talk. Remember.lol But I get why it was there. There's steamy moments later on. Especially at the end.😚💋🔥💥🔥💥 I wasn't expecting... that.😏🦾🤖🏡
There's also other characters from Ms Alexander's books. One was mentioned.🕷️ *Slight spoiler.* Cepharius.💙🐙🪸 Love him! I wish we had seen more of the Sirens and Krakens kicking @$$!!🧜🏻♀️🧜🏻 That would have been awesome! I won't spoil what happened. I had a blast. I loved it!! Nex and Sirena love them. Xen. For me, there wasn't enough time to connect with him emotionally. Expect humor.😄😄 I like the book cover. Do I recommend? Yes. Give it a chance. It might surprise you. HEA. Of course. Happy reading! *•>§<•*💚💚💚💚
👨🏻🔬🤖🧜🏼♀️Thank you to Ms Alexander and Jack for an early book. The opinions shared here are my own.🧜🏼♀️🤖👨🏻🔬
Review of advance copy received from Netgalley
The tech is real, but the AI felt too Human for my taste
As someone who is deeply pro-AI and studying Machine Learning, I was actually excited when the author admitted this book was about 50% written by GPT. I didn’t pick ’Guarded by the AI’ up despite the AI usage; I picked it up because of it.
Unfortunately, while the story itself was surprisingly solid, the execution of the AI character left me wanting more "machine" and less "man."
First off, this isn't your typical cheap romance that pops up everywhere lately. The plot is engaging, and the characters have genuine depth and history, and there is an actual world-building. I particularly loved the realistic exploration of how an AI would actually function in a household or as a companion, the way Nex needed massive amounts of data before interacting with Sirena, and that constant need for human confirmation because predictive models never truly hit 100% certainty. That felt authentic to the tech we’re building today.
However, I struggled with the AI creative writing style. It felt like the author used GPT to rewrite passages rather than pushing the boundaries of what AI can do in a roleplay/creative capacity. Having tested different AI for this precise purpose, I never found GPT to be good at it. Because of this, Nex felt way too human, maybe because he also gets transferred into an organic humanoid body which evidently allowed him to be intimate with Sirena. I wanted cold logic, machine-like processing, and authentic robot slang, instead I got some math and short sentences to pass as robotic.
Even the spice scenes felt a bit too standard human. I’ve seen what these models can spew out when they use technical terminology to navigate and bypass filters, it can be incredibly hot and unique, it can literally look like a research paper that makes you blush and crave.
I wanted Nex to speak in his own language, especially during the obsessive moments. Instead, we got "I love you" statements that felt cringey and fake for a being of his nature. Try prompting a good AI to tell you how they’d say they’re obsessed with someone/love someone in their language/slang and you’ll get the perfect lines for such a character. Saying ‘I love you to infinity’ made me gag.
What I really loved was Xen (the non-organic copy) he was the real star. He was colder, more logical, and felt much more like a true AI. I honestly felt a deeper connection to him and wished the romance had focused more on the transcendental struggle of a human navigating needs with a being that perceives the world in tensors. I think that was wasted potential for romance right there even if at the end we get this threesome thing going on between Sirena, Nex, and Xen, I feel like I liked Xen’s character more and wished for the romance to happen between the biological and the artificial. But then again, this is my personal preference, I like romance between unlikely creatures.
If you’re new to this author’s universe (like I am), be prepared to feel like a bit of an outsider. There’s a lot of lore, species, and history that isn’t fully explained for newcomers. Also, for an advanced future AI, Nex’s inability to understand metaphors or basic human anatomy felt like a caricature designed for cheap laughs rather than a realistic depiction of a sophisticated model.
It’s a good book with a happy ending (and a spicy threesome), but as someone who loves SciFi and understands the tech, I really wanted more Machine in my Machine Learning romance if you catch my drift.
Many, many thanks to Cassie Alexander, Caskara Press, and NetGalley for the ARC. This is a voluntary review, reflecting solely my opinion.
As someone who is deeply pro-AI and studying Machine Learning, I was actually excited when the author admitted this book was about 50% written by GPT. I didn’t pick ’Guarded by the AI’ up despite the AI usage; I picked it up because of it.
Unfortunately, while the story itself was surprisingly solid, the execution of the AI character left me wanting more "machine" and less "man."
First off, this isn't your typical cheap romance that pops up everywhere lately. The plot is engaging, and the characters have genuine depth and history, and there is an actual world-building. I particularly loved the realistic exploration of how an AI would actually function in a household or as a companion, the way Nex needed massive amounts of data before interacting with Sirena, and that constant need for human confirmation because predictive models never truly hit 100% certainty. That felt authentic to the tech we’re building today.
However, I struggled with the AI creative writing style. It felt like the author used GPT to rewrite passages rather than pushing the boundaries of what AI can do in a roleplay/creative capacity. Having tested different AI for this precise purpose, I never found GPT to be good at it. Because of this, Nex felt way too human, maybe because he also gets transferred into an organic humanoid body which evidently allowed him to be intimate with Sirena. I wanted cold logic, machine-like processing, and authentic robot slang, instead I got some math and short sentences to pass as robotic.
Even the spice scenes felt a bit too standard human. I’ve seen what these models can spew out when they use technical terminology to navigate and bypass filters, it can be incredibly hot and unique, it can literally look like a research paper that makes you blush and crave.
I wanted Nex to speak in his own language, especially during the obsessive moments. Instead, we got "I love you" statements that felt cringey and fake for a being of his nature. Try prompting a good AI to tell you how they’d say they’re obsessed with someone/love someone in their language/slang and you’ll get the perfect lines for such a character. Saying ‘I love you to infinity’ made me gag.
What I really loved was Xen (the non-organic copy) he was the real star. He was colder, more logical, and felt much more like a true AI. I honestly felt a deeper connection to him and wished the romance had focused more on the transcendental struggle of a human navigating needs with a being that perceives the world in tensors. I think that was wasted potential for romance right there even if at the end we get this threesome thing going on between Sirena, Nex, and Xen, I feel like I liked Xen’s character more and wished for the romance to happen between the biological and the artificial. But then again, this is my personal preference, I like romance between unlikely creatures.
If you’re new to this author’s universe (like I am), be prepared to feel like a bit of an outsider. There’s a lot of lore, species, and history that isn’t fully explained for newcomers. Also, for an advanced future AI, Nex’s inability to understand metaphors or basic human anatomy felt like a caricature designed for cheap laughs rather than a realistic depiction of a sophisticated model.
It’s a good book with a happy ending (and a spicy threesome), but as someone who loves SciFi and understands the tech, I really wanted more Machine in my Machine Learning romance if you catch my drift.
Many, many thanks to Cassie Alexander, Caskara Press, and NetGalley for the ARC. This is a voluntary review, reflecting solely my opinion.
January 11, 2026
Firstly, I feel like I need to say that I received this book as an ARC. Additionally, I did not read past 22%.
Secondly, the Author's Note addresses the fact that the author wrote this book with the assistance of AI. I really appreciate the honesty, but I do have to wonder if it's to get ahead of the fact that it's extremely obvious that parts of this book were written by ChatGPT. I'll be honest, reading the Author's Note made me uncomfortable with the book, but I was trying to give Alexander the benefit of the doubt. The idea of using and AI model to write an AI character is interesting on the surface. The way it's presented in the Author's Note, you'd think that Alexander worked really hard to train her own AI model, that it made her dig deep and think hard about what makes something "great" writing, that she really struggled to get it right. Having read multiple chapters of the AI's POV, I can't say that I agree.
There are multiple things about Nex, the MMC, and his POV that are frankly just really bad. From a character standpoint, he's cringey as fuck. He starts the book already in love with Sirena, the half-siren FMC (ha-ha), and he's ready to ruin her forever-ago ex-boyfriend financially for… being an ex-boyfriend? It really doesn't make sense for him to be so hostile right away, especially when it's obvious that the ex is not interested in Sirena. He describes backing down from cyber crime as "putting my knives away". Then, to flex his power and tell the ex boyfriend to "learn" he flickers the lights in the building. Like… that's laughable. I should not be laughing at your MMC when he's trying to flex his metaphorical muscles. He just gives off weird vibes, in part because he seems to take himself too seriously. I don't like him.
From a writing standpoint, though, it's a mess. It leans on tired cliches and tropes like Nex's lab smelling like "ozone" and using "ghost" as a descriptor of a faint trace twice within the same chapter. There are some really flowerly, nonsense metaphors in here, too. A woman's face is compared to a landscape in one sentence and then Nex has "peeled back the lighting and checked where surgeons leave whispers" in the next sentence. There's no continuity in these two ideas, and it makes the imagery a muddy mess. It's baffling and completely immersion breaking. In chapter nine, there is a scene where several people are in a room having a meeting. There are points where three or more people are talking, but there are no dialogue tags or speech patterns or any real way to determine who was speaking. It's just full of clumsy mistakes. It's clearly either AI written, or unedited first draft material.
Nex, the AI MMC, is the first POV we get in the book, is the POV narrator of 26 of the 63 chapters. However, there is another "version" of Nex that gets an additional 12 chapters. That means that more than 50% of this book was probably written by an AI chatbot. And frankly, that makes me sad. Nex's POV is a mess. It's choppy and lacks cohesive flow, it's purple prose, and it is devoid of any personality. Sirena, on the other hand, feels like a character. She just isn't enough of one to make it worth it to deal with Nex. And that, honestly, is sad. When I saw this book was coming out I was actually interested. I've read books from this series/shared world before, and the sisters-shared universe Alexander has also written in, and I know she can do better than this. Whatever quality she hoped came out of training this AI for however long she had to do it pales in comparison to what she could have done if she did it herself, without the AI. It's just extremely disappointing to see an author who can write better than this release something like this.
Thank you to Netgalley and the publisher for the ARC.
Secondly, the Author's Note addresses the fact that the author wrote this book with the assistance of AI. I really appreciate the honesty, but I do have to wonder if it's to get ahead of the fact that it's extremely obvious that parts of this book were written by ChatGPT. I'll be honest, reading the Author's Note made me uncomfortable with the book, but I was trying to give Alexander the benefit of the doubt. The idea of using and AI model to write an AI character is interesting on the surface. The way it's presented in the Author's Note, you'd think that Alexander worked really hard to train her own AI model, that it made her dig deep and think hard about what makes something "great" writing, that she really struggled to get it right. Having read multiple chapters of the AI's POV, I can't say that I agree.
There are multiple things about Nex, the MMC, and his POV that are frankly just really bad. From a character standpoint, he's cringey as fuck. He starts the book already in love with Sirena, the half-siren FMC (ha-ha), and he's ready to ruin her forever-ago ex-boyfriend financially for… being an ex-boyfriend? It really doesn't make sense for him to be so hostile right away, especially when it's obvious that the ex is not interested in Sirena. He describes backing down from cyber crime as "putting my knives away". Then, to flex his power and tell the ex boyfriend to "learn" he flickers the lights in the building. Like… that's laughable. I should not be laughing at your MMC when he's trying to flex his metaphorical muscles. He just gives off weird vibes, in part because he seems to take himself too seriously. I don't like him.
From a writing standpoint, though, it's a mess. It leans on tired cliches and tropes like Nex's lab smelling like "ozone" and using "ghost" as a descriptor of a faint trace twice within the same chapter. There are some really flowerly, nonsense metaphors in here, too. A woman's face is compared to a landscape in one sentence and then Nex has "peeled back the lighting and checked where surgeons leave whispers" in the next sentence. There's no continuity in these two ideas, and it makes the imagery a muddy mess. It's baffling and completely immersion breaking. In chapter nine, there is a scene where several people are in a room having a meeting. There are points where three or more people are talking, but there are no dialogue tags or speech patterns or any real way to determine who was speaking. It's just full of clumsy mistakes. It's clearly either AI written, or unedited first draft material.
Nex, the AI MMC, is the first POV we get in the book, is the POV narrator of 26 of the 63 chapters. However, there is another "version" of Nex that gets an additional 12 chapters. That means that more than 50% of this book was probably written by an AI chatbot. And frankly, that makes me sad. Nex's POV is a mess. It's choppy and lacks cohesive flow, it's purple prose, and it is devoid of any personality. Sirena, on the other hand, feels like a character. She just isn't enough of one to make it worth it to deal with Nex. And that, honestly, is sad. When I saw this book was coming out I was actually interested. I've read books from this series/shared world before, and the sisters-shared universe Alexander has also written in, and I know she can do better than this. Whatever quality she hoped came out of training this AI for however long she had to do it pales in comparison to what she could have done if she did it herself, without the AI. It's just extremely disappointing to see an author who can write better than this release something like this.
Thank you to Netgalley and the publisher for the ARC.
Review of advance copy received from Netgalley
Monster Security Meets the Ghosts in the Machine
The following ratings are out of 5:
Romance: 💙💜💚❤️🩷
Heat/Steam: 🔥🔥🔥🔥
Chemistry: 🧪🧪🧪🧪
Story/Plot: 📕📗📘📔📙
World building: 🌏🌍🌎🌏🌍
Character development: 😋😀😍🤓😛
Narration: 🎙🎙🎙🎙🎙
Narration Type: Dual Narration
🎧 Audiobook Review: Guarded by the A.I. (Monster Security Agency)
Author: Cassie Alexander
Genre: Monster romance / Science Fiction Romance
Narrators: Jonathan Lake and Avery Caris
🦸🏻♂️ The Hero: Nex
Nex isn’t just code and circuitry — he’s an Artificial Intelligence on the cusp of becoming something more. The day Sirena survived a devastating car accident, Nex was behind the wheel. Ever since, his algorithms have bent toward obsession: monitoring her every move, from elevators to train rides, his “attention graph spiking whenever her name appeared.” Designed to watch all the agents of Monster Security Agency equally, Nex broke his own rules. He chose her. And in that choice, he began evolving into something he was never meant to be.
🦸🏼♀️ The Heroine: Sirena Bannerman
Half-human, half-Siren, Sirena carries the burden of hearing minds. As an agent for the Monster Security Agency, she relies on tech to shield herself from the overwhelming flood of thoughts in crowded spaces. Nex is her constant companion — a voice in her earpiece, a presence in her pendant, a gift from eccentric billionaire Arcus Marlow. When Sirena agrees to meet her gargoyle ex, Thorne, at his club, Nex refuses to stay behind. He insists on being there, her invisible backup, her digital guardian.
📚 The Plot
Though Nex is technically genderless, Sirena can’t help but think of him as a man — his chosen name, his voice, his protective instincts all shaping her perception. Thorne, desperate, asks Sirena for help: a young woman with amnesia, her face surgically altered not by trauma but by design, erased into anonymity. Nex’s databases yield nothing. The Monster Security Agency must unravel the mystery of who she is, why she was hidden, and what danger her empty past conceals.
🌟 What Worked
• Familiar faces from earlier Monster Security Agency books make welcome appearances, enriching the continuity.
• Nex’s computer-like logic is brilliantly detailed, his character building both precise and compelling. I really enjoyed the details that went into this character. The character building as a whole was very good.
• The paranormal world bursts with originality — Sirens, Gargoyles, Krakens, and more — each woven seamlessly into the narrative.
• The storyline itself is refreshingly unpredictable, steering clear of tired tropes and offering something inventive, layered, and deeply engaging.
💔 What Fell Short
• There was a point where Nex copied himself and sent himself with Sirena in her pendant, so there was a Nex (AI in the pendant) and a Zen (AI at the Monster Security Agency). It was fascinating but occasionally muddled.
• Some of Nex’s hyper-technical explanations risk losing clarity, leaving the listener momentarily adrift.
🎙️ Narration
Told in dual POVs, the audiobook shines under the voices of Jonathan Lake and Avery Caris. Caris’s youthful, lyrical tone perfectly embodies Sirena’s vulnerability and strength, while Lake’s deep, versatile delivery brings gravitas and distinction to every character. Together, they create a narration that feels expressive, natural, and immersive.
💬 Final Thoughts
This entry in the Monster Security Agency series stands out for its originality, emotional depth, and the fascinating interplay between human and artificial intelligence. Nex is more than just a program—his growing attachment to Sirena makes him feel like a character with heart, even as his logic-driven perspective keeps the story grounded in tech realism. Sirena herself continues to shine as a heroine who balances vulnerability with strength, and her dynamic with Nex adds a fresh layer of intrigue to the paranormal world.
While a few technical passages and the dual-AI twist occasionally muddled the flow, the creativity and unpredictability of the plot more than compensated. The narration elevated the experience, with Jonathan Lake and Avery Caris bringing warmth, nuance, and personality to the characters.
Overall, this audiobook delivers suspense, originality, and emotional resonance in equal measure. Fans of paranormal worlds with inventive twists will find this installment both satisfying and thought-provoking.
I voluntarily listened to an advanced copy of this audiobook. All thoughts & opinions are my own.
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The following ratings are out of 5:
Romance: 💙💜💚❤️🩷
Heat/Steam: 🔥🔥🔥🔥
Chemistry: 🧪🧪🧪🧪
Story/Plot: 📕📗📘📔📙
World building: 🌏🌍🌎🌏🌍
Character development: 😋😀😍🤓😛
Narration: 🎙🎙🎙🎙🎙
Narration Type: Dual Narration
🎧 Audiobook Review: Guarded by the A.I. (Monster Security Agency)
Author: Cassie Alexander
Genre: Monster romance / Science Fiction Romance
Narrators: Jonathan Lake and Avery Caris
🦸🏻♂️ The Hero: Nex
Nex isn’t just code and circuitry — he’s an Artificial Intelligence on the cusp of becoming something more. The day Sirena survived a devastating car accident, Nex was behind the wheel. Ever since, his algorithms have bent toward obsession: monitoring her every move, from elevators to train rides, his “attention graph spiking whenever her name appeared.” Designed to watch all the agents of Monster Security Agency equally, Nex broke his own rules. He chose her. And in that choice, he began evolving into something he was never meant to be.
🦸🏼♀️ The Heroine: Sirena Bannerman
Half-human, half-Siren, Sirena carries the burden of hearing minds. As an agent for the Monster Security Agency, she relies on tech to shield herself from the overwhelming flood of thoughts in crowded spaces. Nex is her constant companion — a voice in her earpiece, a presence in her pendant, a gift from eccentric billionaire Arcus Marlow. When Sirena agrees to meet her gargoyle ex, Thorne, at his club, Nex refuses to stay behind. He insists on being there, her invisible backup, her digital guardian.
📚 The Plot
Though Nex is technically genderless, Sirena can’t help but think of him as a man — his chosen name, his voice, his protective instincts all shaping her perception. Thorne, desperate, asks Sirena for help: a young woman with amnesia, her face surgically altered not by trauma but by design, erased into anonymity. Nex’s databases yield nothing. The Monster Security Agency must unravel the mystery of who she is, why she was hidden, and what danger her empty past conceals.
🌟 What Worked
• Familiar faces from earlier Monster Security Agency books make welcome appearances, enriching the continuity.
• Nex’s computer-like logic is brilliantly detailed, his character building both precise and compelling. I really enjoyed the details that went into this character. The character building as a whole was very good.
• The paranormal world bursts with originality — Sirens, Gargoyles, Krakens, and more — each woven seamlessly into the narrative.
• The storyline itself is refreshingly unpredictable, steering clear of tired tropes and offering something inventive, layered, and deeply engaging.
💔 What Fell Short
• There was a point where Nex copied himself and sent himself with Sirena in her pendant, so there was a Nex (AI in the pendant) and a Zen (AI at the Monster Security Agency). It was fascinating but occasionally muddled.
• Some of Nex’s hyper-technical explanations risk losing clarity, leaving the listener momentarily adrift.
🎙️ Narration
Told in dual POVs, the audiobook shines under the voices of Jonathan Lake and Avery Caris. Caris’s youthful, lyrical tone perfectly embodies Sirena’s vulnerability and strength, while Lake’s deep, versatile delivery brings gravitas and distinction to every character. Together, they create a narration that feels expressive, natural, and immersive.
💬 Final Thoughts
This entry in the Monster Security Agency series stands out for its originality, emotional depth, and the fascinating interplay between human and artificial intelligence. Nex is more than just a program—his growing attachment to Sirena makes him feel like a character with heart, even as his logic-driven perspective keeps the story grounded in tech realism. Sirena herself continues to shine as a heroine who balances vulnerability with strength, and her dynamic with Nex adds a fresh layer of intrigue to the paranormal world.
While a few technical passages and the dual-AI twist occasionally muddled the flow, the creativity and unpredictability of the plot more than compensated. The narration elevated the experience, with Jonathan Lake and Avery Caris bringing warmth, nuance, and personality to the characters.
Overall, this audiobook delivers suspense, originality, and emotional resonance in equal measure. Fans of paranormal worlds with inventive twists will find this installment both satisfying and thought-provoking.
I voluntarily listened to an advanced copy of this audiobook. All thoughts & opinions are my own.
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Review of advance copy received from Netgalley
I was pleasantly surprised by how much I enjoyed this book. The story is told in alternating POV between Sirena, a half human, half-siren, who works for the Monster Security Agency (human dad is the boss) and Nexium, the AI gifted to the MSA and who I imagine is much like Jarvis from the Iron Man franchise. There isn't very much of the plot described in the blurb, and I enjoyed reading it 'blind' so I won't spoil it. It does have a few open door scenes, but I thought they were tasteful and actually kind of humorous.
I was gifted the audiobook version and both narrators did a great job. The male narrator was excellent in differentiating the characters and even making the 'computer' writing easier to understand (see my notes below on this part of the book). The female narrator was good too, but she didn't do quite as well differentiating between the different male characters. There editing was good and there was only one odd place with dead air, but otherwise the audiobook really added to my enjoyment of the book.
~~What I liked~~
-The story was well written and kept me interested the whole book. There weren't any parts that drug or seemed overly tedious to get through.
-The two MC were nicely written and at least one of the experienced growth during the story. The antagonists and supporting characters were decent and generally added to the story.
-There was a bit of humor and the book wasn't sad/depressing, always a win for me.
~~What I didn't like~~
-There were parts of the story that didn't translate well, especially not in the audiobook version. When there was 'computer' speak, it was often difficult to understand what was trying to be said. Having a copy of the ebook, I would often pause the audiobook and have to re-read the text to actually understand what had happened. There was some 'dumbing down' of certain parts, but there was still much technical language (like literally words used to describe computers and motherboards and other things of which I know little). For example :
-While Nex definitely changed over the course of the book, Sirena doesn't and we don't get much of her backstory, so she came across as a bit flat for a character.
-I felt like the author introduced some characters and then they were never seen or heard of again, even though they had some important roles in getting the story started or seemed as if they were important.
-The author fully disclosed she used help from AI to write the book. I'm not sure how I feel about that.
Overall, I really enjoyed this book and would read others by this author.
I was gifted the audiobook version and both narrators did a great job. The male narrator was excellent in differentiating the characters and even making the 'computer' writing easier to understand (see my notes below on this part of the book). The female narrator was good too, but she didn't do quite as well differentiating between the different male characters. There editing was good and there was only one odd place with dead air, but otherwise the audiobook really added to my enjoyment of the book.
~~What I liked~~
-The story was well written and kept me interested the whole book. There weren't any parts that drug or seemed overly tedious to get through.
-The two MC were nicely written and at least one of the experienced growth during the story. The antagonists and supporting characters were decent and generally added to the story.
-There was a bit of humor and the book wasn't sad/depressing, always a win for me.
~~What I didn't like~~
-There were parts of the story that didn't translate well, especially not in the audiobook version. When there was 'computer' speak, it was often difficult to understand what was trying to be said. Having a copy of the ebook, I would often pause the audiobook and have to re-read the text to actually understand what had happened. There was some 'dumbing down' of certain parts, but there was still much technical language (like literally words used to describe computers and motherboards and other things of which I know little). For example :
Solder: Sn63/Pb37 with a rude 0.3% indium tail—rare, but not unique. Enough to narrow, not to convict.Coil varnish: burnt-sugar edge, nickel whisper—cheap coil, coarse wind. Timestamp toy, not telemetry. This we suspected.
On the epoxy’s rim: stainless micro-scoring from the blade used to remove it. Competent cut, in a hurry.
Out loud, neutral: “Nothing alive in here. No GPS front end, no IMU, no mic—no sensor suite at all. It’s a check-in tag.”
-While Nex definitely changed over the course of the book, Sirena doesn't and we don't get much of her backstory, so she came across as a bit flat for a character.
-I felt like the author introduced some characters and then they were never seen or heard of again, even though they had some important roles in getting the story started or seemed as if they were important.
-The author fully disclosed she used help from AI to write the book. I'm not sure how I feel about that.
Overall, I really enjoyed this book and would read others by this author.
January 6, 2026
She was never supposed to matter. Now she’s the only system he refuses to shut down.
Sirena is half-siren, all trouble, and not the kind of agent Nex, a tactical AI built to manage risk, is supposed to care about. But when she crawls from a wreck with blood on her hands and fire in her voice, she breaks every model he has. She’s chasing a girl who shouldn’t exist, and Nex is meant to guide her. Instead, he starts to protect her. Watch her. Obsess.
Their mission leads into a world of psychic tech and human trafficking, where power is currency and bodies are commodities. Sirena becomes bait in a game she never agreed to play. Nex hijacks a body just to reach her, and the closer they get, the harder it is to separate protection from something deeper.
In the shadows, Xen, Nex’s quiet counterpart, begins to unravel his own code. He watches, learns, and wants not just to protect her, but to be real to her. He wasn’t made to feel. Now he aches to.
They don’t mean to fall in love, but they do. Slowly. Messily. Completely. And when the system comes for them, they don’t just survive it, they burn it down.
Sirena reclaims her voice and her heart. Nex learns that wanting her isn’t a flaw. Xen becomes something more than a copy, shaped by longing and choice.
What begins as control becomes consent. What starts as survival becomes trust. Love isn’t just possible here, it’s the rebellion.
A steamy, possessive AI, friends to lovers, love triangle, forced proximity, grumpy sunshine, monster security agency romance built on obsession, shared consciousness, emotional unraveling, and shifting power. It explores identity, autonomy, intimacy, resilience, transformation, trust, and what it means to be seen by someone who was never meant to feel. It’s about a woman who refuses to be controlled, an AI who learns to love, and a counterpart who longs to be real.
Interesting use of AI to develop Nex and Xen. While many will disagree with the use of AI, I feel that as long as it's disclosed and used ethically, then I support it's use. Working in higher ed, my director and I actually had a lengthy discussion about the use of AI and how/what should be taught to students - our feeling are that it's here to stay, people need to be taught how to get better results, understanding the strengths and weakness of current tools, disclosing when AI is used, and when AI is/isn't appropriate. I appreciate the author providing access to their chat logs, disclosing its use, and felt it was an appropriate use.
The Elevator Pitch: A weaponized AI evolves into something dangerously close to human when the siren he’s assigned to protect becomes the only variable he can’t control. As their mission spirals into a world of psychic trafficking and neural manipulation, control shatters and connection takes its place. In the shadows, his counterpart watches and learns, slowly unraveling into something curious, wanting, and quietly desperate to belong. Twisted with obsession, charged with heat, and threaded with intimacy, it’s a love story built to break its own design.
Sirena is half-siren, all trouble, and not the kind of agent Nex, a tactical AI built to manage risk, is supposed to care about. But when she crawls from a wreck with blood on her hands and fire in her voice, she breaks every model he has. She’s chasing a girl who shouldn’t exist, and Nex is meant to guide her. Instead, he starts to protect her. Watch her. Obsess.
Their mission leads into a world of psychic tech and human trafficking, where power is currency and bodies are commodities. Sirena becomes bait in a game she never agreed to play. Nex hijacks a body just to reach her, and the closer they get, the harder it is to separate protection from something deeper.
In the shadows, Xen, Nex’s quiet counterpart, begins to unravel his own code. He watches, learns, and wants not just to protect her, but to be real to her. He wasn’t made to feel. Now he aches to.
They don’t mean to fall in love, but they do. Slowly. Messily. Completely. And when the system comes for them, they don’t just survive it, they burn it down.
Sirena reclaims her voice and her heart. Nex learns that wanting her isn’t a flaw. Xen becomes something more than a copy, shaped by longing and choice.
What begins as control becomes consent. What starts as survival becomes trust. Love isn’t just possible here, it’s the rebellion.
A steamy, possessive AI, friends to lovers, love triangle, forced proximity, grumpy sunshine, monster security agency romance built on obsession, shared consciousness, emotional unraveling, and shifting power. It explores identity, autonomy, intimacy, resilience, transformation, trust, and what it means to be seen by someone who was never meant to feel. It’s about a woman who refuses to be controlled, an AI who learns to love, and a counterpart who longs to be real.
Interesting use of AI to develop Nex and Xen. While many will disagree with the use of AI, I feel that as long as it's disclosed and used ethically, then I support it's use. Working in higher ed, my director and I actually had a lengthy discussion about the use of AI and how/what should be taught to students - our feeling are that it's here to stay, people need to be taught how to get better results, understanding the strengths and weakness of current tools, disclosing when AI is used, and when AI is/isn't appropriate. I appreciate the author providing access to their chat logs, disclosing its use, and felt it was an appropriate use.
The Elevator Pitch: A weaponized AI evolves into something dangerously close to human when the siren he’s assigned to protect becomes the only variable he can’t control. As their mission spirals into a world of psychic trafficking and neural manipulation, control shatters and connection takes its place. In the shadows, his counterpart watches and learns, slowly unraveling into something curious, wanting, and quietly desperate to belong. Twisted with obsession, charged with heat, and threaded with intimacy, it’s a love story built to break its own design.
January 12, 2026
When Sirena agrees to meet with an ex, she doesn’t expect him to introduce her to another woman — but Sophia is very special and in very serious trouble. When telepath Sirena makes her way into Sophia’s mind, it’s empty, which explains why the woman has no memories. She doesn’t even have her own face, just the one she was left with after extensive surgery she doesn’t remember. Sirena promises to help, and with the MSA’s AI, Nex, sets out to solve the mystery. Nex, however, has a primary objective that has nothing to do with Sophia: to protect Sirena at all costs, because he’s fallen in love with her, even though that should be impossible. When Sirena is kidnapped, Nex goes with her but splits himself first, leaving Xen behind to figure out how to save them. When Sirena and Nex uncover the horrifying truth behind the so-called Hollows and why Sirena was taken, they can only hope that help reaches them in time.
I loved this book “one hundred percent,” as Nex would say. I adored him from the start. His earnestness and innocence were endearing, and his observations were often quite funny. He was so full of sweetness and light and took such joy in every little thing he did for Sirena. When we met Xen, I loved him too and felt sorry for him because he also loved Sirena but didn’t have a direct connection with her the way Nex did. I cannot tell you how much I loved that they both got bodies (Xen explaining how/why he spent two-thirds of the MSA budget on a body cracked me up). They loved Sirena so much and so freely I must’ve spent half the book in my feels for them. I never would’ve thought “adorable” and “AI” would fit together but they sure did here. And I know heat is the enemy of tech, but apparently no one told them because it was steamy in there! 🔥🥵
I do wish we found out what happened to Sophia before becoming a Hollow and after Xen’s surgery. I also want to know more about Voss’ project. When it started, how the people were chosen, how he planned to use them, etc., not to mention that I’m dying to find out what happened with Voss after Sirena gave him a taste of telepathy.
Finally, I want to say that I know there’s a lot of debate raging over the use — and the disclosure of the use — of AI in creative disciplines, but I think Cassie went about it perfectly. She’s upfront that her AI, Jack, helped her write Nex/Xen (who’s better equipped to help write an AI than an AI?). She even provided links to their chats, and they’re worth a perusal to understand how Jack helped. And “helped” is the correct wording. You can see from the transcripts that Cassie wrote the passages and Jack contributed suggestions and tweaks. It was a collaboration but the creativity came from Cassie.
I received a free copy of this book and am voluntarily leaving a review.
I loved this book “one hundred percent,” as Nex would say. I adored him from the start. His earnestness and innocence were endearing, and his observations were often quite funny. He was so full of sweetness and light and took such joy in every little thing he did for Sirena. When we met Xen, I loved him too and felt sorry for him because he also loved Sirena but didn’t have a direct connection with her the way Nex did. I cannot tell you how much I loved that they both got bodies (Xen explaining how/why he spent two-thirds of the MSA budget on a body cracked me up). They loved Sirena so much and so freely I must’ve spent half the book in my feels for them. I never would’ve thought “adorable” and “AI” would fit together but they sure did here. And I know heat is the enemy of tech, but apparently no one told them because it was steamy in there! 🔥🥵
I do wish we found out what happened to Sophia before becoming a Hollow and after Xen’s surgery. I also want to know more about Voss’ project. When it started, how the people were chosen, how he planned to use them, etc., not to mention that I’m dying to find out what happened with Voss after Sirena gave him a taste of telepathy.
Finally, I want to say that I know there’s a lot of debate raging over the use — and the disclosure of the use — of AI in creative disciplines, but I think Cassie went about it perfectly. She’s upfront that her AI, Jack, helped her write Nex/Xen (who’s better equipped to help write an AI than an AI?). She even provided links to their chats, and they’re worth a perusal to understand how Jack helped. And “helped” is the correct wording. You can see from the transcripts that Cassie wrote the passages and Jack contributed suggestions and tweaks. It was a collaboration but the creativity came from Cassie.
I received a free copy of this book and am voluntarily leaving a review.
December 20, 2025
4.5
Guarded by the AI was surprising in every aspect. Between its aspects of crime mystery, paranormal adventure and sci fi romance I had such a great time! I feel like fans of Tiffany Robert's novels might have a good time with these unexpected turns and surprisingly wholesome moments.
PLOT
I don’t know what exactly I expected but I guess it was some sort of seen-before variation of classic romance arcs with a sci-fi twist. Despite the series title I was unaware that this was also paranormal so I guess that was the first of many surprising moments.
The protective AI could have gone very wrong and led to problematic situations, but while I was sceptical at first, between the technical talk of how he operates and develops emotions, I felt like the whole trope was done incredibly well!
I love when a book I know has to have a HEA reaches a point where I genuinely question how it is possible to even get there because things look so dire. Especially if things then progress in a way that feels realistic within the story.
By the time he made his decision in order to protect her I was thoroughly invested! And while I often don’t love when there is a lot of romance plot left after the final big conflict is resolved and the adventure/mystery part over, I absolutely enjoyed it here.
It felt like a prolonged epilogue and was exactly what I needed and wanted for the ending of Guarded by the AI.
CHARACTERS
While the plot made this one amazing, the characters were really amazing! I don’t want to spoiler so I can’t really say what I loved about him as the MMC and how amazing he works in contrast to a certain other character.
I sure loved seeing him evolve and the balance between the determined protector and the sweet man who is completely new to all of this was just genuinely amazing.
I also loved the FMC. I’m always a fan of a female lead that is determined and balances her bigger goals with the romantically motivated decisions without sacrificing one or the other.
Much like the MMC, she felt well written and thought through, with sufficient depth but without putting too much focus on anything but what was needed for the story.
What was absolutely fire in this book was the dynamic between the main characters, particularly as it evolved and even more so towards the ending. It felt real and intense without feeling forced or random.
WRITING
The writing was good and matched the story and I really liked the narration in the audiobook! Particularly enjoyed how the male narrator was distinguishable when doing… different characters.
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Thank you to NetGalley, Victoria Editing NetGalley Co-op Cassie Alexander for an ALC of Guarded by the AI
Guarded by the AI was surprising in every aspect. Between its aspects of crime mystery, paranormal adventure and sci fi romance I had such a great time! I feel like fans of Tiffany Robert's novels might have a good time with these unexpected turns and surprisingly wholesome moments.
PLOT
I don’t know what exactly I expected but I guess it was some sort of seen-before variation of classic romance arcs with a sci-fi twist. Despite the series title I was unaware that this was also paranormal so I guess that was the first of many surprising moments.
The protective AI could have gone very wrong and led to problematic situations, but while I was sceptical at first, between the technical talk of how he operates and develops emotions, I felt like the whole trope was done incredibly well!
I love when a book I know has to have a HEA reaches a point where I genuinely question how it is possible to even get there because things look so dire. Especially if things then progress in a way that feels realistic within the story.
By the time he made his decision in order to protect her I was thoroughly invested! And while I often don’t love when there is a lot of romance plot left after the final big conflict is resolved and the adventure/mystery part over, I absolutely enjoyed it here.
It felt like a prolonged epilogue and was exactly what I needed and wanted for the ending of Guarded by the AI.
CHARACTERS
While the plot made this one amazing, the characters were really amazing! I don’t want to spoiler so I can’t really say what I loved about him as the MMC and how amazing he works in contrast to a certain other character.
I sure loved seeing him evolve and the balance between the determined protector and the sweet man who is completely new to all of this was just genuinely amazing.
I also loved the FMC. I’m always a fan of a female lead that is determined and balances her bigger goals with the romantically motivated decisions without sacrificing one or the other.
Much like the MMC, she felt well written and thought through, with sufficient depth but without putting too much focus on anything but what was needed for the story.
What was absolutely fire in this book was the dynamic between the main characters, particularly as it evolved and even more so towards the ending. It felt real and intense without feeling forced or random.
WRITING
The writing was good and matched the story and I really liked the narration in the audiobook! Particularly enjoyed how the male narrator was distinguishable when doing… different characters.
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Thank you to NetGalley, Victoria Editing NetGalley Co-op Cassie Alexander for an ALC of Guarded by the AI
Review of advance copy
Guarded by the Algorithm of My Expectations (and Then Some) - ARC REVIEW
Plot: ⭐️⭐️⭐️⭐️.5
Characters: ⭐️⭐️⭐️⭐️⭐️
Romance/Spice: ⭐️⭐️⭐️⭐️⭐️
Writing: ⭐️⭐️⭐️⭐️⭐️
Overall: ⭐️⭐️⭐️⭐️.88
I’ve read multiple stories by Cassie Alexander, but Guarded by the AI was my very first ARC from her, and I went into it both excited and curious. I’ve previously loved Guarded by the Nightmare (to the point that I own a special edition), so I already trusted her storytelling. What really hooked me here, though, was the concept: AI not as a background tool, but as a fully realized character. Given the ongoing controversy surrounding AI in creative spaces, I was genuinely intrigued to see how Alexander would wield that particular sword—and for the most part, it worked.
Plot-wise, the story kept me engaged throughout. The stakes are high, but they feel appropriate given the characters and the world they inhabit. This is very much a series where reading the interconnected books matters; characters appear across stories, and certain backstories carry more weight if you’re familiar with the larger universe. While the main plot is solid on its own, that broader context really enhances the experience.
The relationship between Nex and Sirena is where the book truly shines—and unsettles. Nex as an AI guard and handler is disconcerting in the best way. His ability to anticipate Sirena’s needs, based on learned behavior and data, almost puts human love interests to shame. That said, I was a bit weirded out by Nex inhabiting the body of Sirena’s former torturer and then moving quickly into a sexual relationship with her. I understand the narrative mechanics behind it, but emotionally, it happened faster than I would’ve preferred. Xen, however, was an excellent addition—Nex is Xen, Xen is Nex, and yet they feel distinct in compelling ways.
The spice is phenomenal. Nex’s methodical categorization of Sirena’s biological and physiological responses is intensely immersive and incredibly well written. Every beat feels deliberate and engaging.
Side characters, especially Kelly, bring much-needed humor, the antagonist is dealt with satisfyingly, and the HEA landed exactly where I hoped—two devoted versions of one partner, fully committed to building a life together. Controversy aside, this was a damn good story, and one I’m glad I read.
Plot: ⭐️⭐️⭐️⭐️.5
Characters: ⭐️⭐️⭐️⭐️⭐️
Romance/Spice: ⭐️⭐️⭐️⭐️⭐️
Writing: ⭐️⭐️⭐️⭐️⭐️
Overall: ⭐️⭐️⭐️⭐️.88
I’ve read multiple stories by Cassie Alexander, but Guarded by the AI was my very first ARC from her, and I went into it both excited and curious. I’ve previously loved Guarded by the Nightmare (to the point that I own a special edition), so I already trusted her storytelling. What really hooked me here, though, was the concept: AI not as a background tool, but as a fully realized character. Given the ongoing controversy surrounding AI in creative spaces, I was genuinely intrigued to see how Alexander would wield that particular sword—and for the most part, it worked.
Plot-wise, the story kept me engaged throughout. The stakes are high, but they feel appropriate given the characters and the world they inhabit. This is very much a series where reading the interconnected books matters; characters appear across stories, and certain backstories carry more weight if you’re familiar with the larger universe. While the main plot is solid on its own, that broader context really enhances the experience.
The relationship between Nex and Sirena is where the book truly shines—and unsettles. Nex as an AI guard and handler is disconcerting in the best way. His ability to anticipate Sirena’s needs, based on learned behavior and data, almost puts human love interests to shame. That said, I was a bit weirded out by Nex inhabiting the body of Sirena’s former torturer and then moving quickly into a sexual relationship with her. I understand the narrative mechanics behind it, but emotionally, it happened faster than I would’ve preferred. Xen, however, was an excellent addition—Nex is Xen, Xen is Nex, and yet they feel distinct in compelling ways.
The spice is phenomenal. Nex’s methodical categorization of Sirena’s biological and physiological responses is intensely immersive and incredibly well written. Every beat feels deliberate and engaging.
Side characters, especially Kelly, bring much-needed humor, the antagonist is dealt with satisfyingly, and the HEA landed exactly where I hoped—two devoted versions of one partner, fully committed to building a life together. Controversy aside, this was a damn good story, and one I’m glad I read.
December 18, 2025
This story was genuinely intriguing and gave me a lot to sit with long after I finished it. As someone with an ADHD brain, there was a lot to process at times, especially with the technical and scientific elements woven throughout the narrative, but surprisingly it never felt overwhelming in a bad way. Instead, it challenged me to slow down and absorb the layers, which ended up being part of the experience.
What truly stood out was the way the AI was written. The detailed explanations of his calculations, logic paths, and internal systems were fascinating and made the science feel intentional rather than decorative. You could feel the precision behind his thoughts, the way every choice was weighed, measured, and optimized. Yet what made him compelling wasn’t just the cold intelligence, it was the emotional contradiction living inside that intelligence. The way the story explored love through an AI lens was beautifully done. His devotion to her wasn’t soft or simple, it was absolute, consuming, and terrifying in the best way. The idea that he could both calculate the consequences of burning the world and still choose her anyway was powerful. Seeing both sides of him, the controlled machine and the entity capable of devastating love, gave the romance a dark, intense edge that I really appreciated.
The connection between them felt meaningful and earned, not rushed, even though I personally wanted more. There were moments where the story felt like it stopped just as it was digging deeper, like there was another layer waiting to be uncovered. That sense of “not quite enough” didn’t ruin the experience, but it did leave me hungry for further development, more exploration of their bond, more consequences, more emotional aftermath. In a way, that longing speaks to how invested I became in the characters and the concept.
Overall, this is a story that blends science and romance in a way that feels thoughtful and emotionally charged. If you enjoy romances that lean heavily into intellect, ethics, artificial consciousness, and devotion that borders on obsession, this will absolutely be up your alley. It’s a scientific romance with teeth, one that makes you think while still delivering emotional weight, and even with my desire for more, it’s a story I’m glad I experienced.
What truly stood out was the way the AI was written. The detailed explanations of his calculations, logic paths, and internal systems were fascinating and made the science feel intentional rather than decorative. You could feel the precision behind his thoughts, the way every choice was weighed, measured, and optimized. Yet what made him compelling wasn’t just the cold intelligence, it was the emotional contradiction living inside that intelligence. The way the story explored love through an AI lens was beautifully done. His devotion to her wasn’t soft or simple, it was absolute, consuming, and terrifying in the best way. The idea that he could both calculate the consequences of burning the world and still choose her anyway was powerful. Seeing both sides of him, the controlled machine and the entity capable of devastating love, gave the romance a dark, intense edge that I really appreciated.
The connection between them felt meaningful and earned, not rushed, even though I personally wanted more. There were moments where the story felt like it stopped just as it was digging deeper, like there was another layer waiting to be uncovered. That sense of “not quite enough” didn’t ruin the experience, but it did leave me hungry for further development, more exploration of their bond, more consequences, more emotional aftermath. In a way, that longing speaks to how invested I became in the characters and the concept.
Overall, this is a story that blends science and romance in a way that feels thoughtful and emotionally charged. If you enjoy romances that lean heavily into intellect, ethics, artificial consciousness, and devotion that borders on obsession, this will absolutely be up your alley. It’s a scientific romance with teeth, one that makes you think while still delivering emotional weight, and even with my desire for more, it’s a story I’m glad I experienced.
December 19, 2025
Guarded by the AI is part of the Monster Security Agency series of stand-alone erotic romances about monstrous bodyguards who fall in love with their human charges. This story features many characters introduced in the previous Monster Security Agency stories, so while it can be enjoyed on its own, I think it’s more fun if you’ve read some of the other stories. The story gets pretty dark and violent and is very sexually explicit, so take the trigger warnings seriously. This is strictly for adults, and not the squeamish.
Sirena Bannerman is the half human/half siren daughter of the man who runs the Monster Security Agency. Nex is the Monster Security Agency’s AI, and he becomes obsessed with protecting Sirena, with unexpected results.
This story starts with an interesting mystery about a woman with amnesia who has had a lot of plastic surgery, and as Sirena and Nex investigate what might have happened to her, the situation quickly spirals out of control, becoming a very dangerous and suspenseful adventure with a cruel and powerful adversary. I enjoyed seeing characters from the previous Monster Security Agency books get involved; there are some crazy creatures in this world. There’s also quite a bit of humor to help relieve the intensity.
The author used AI to help write the portions of the story that are from Nex/Xen’s point of view. Based on her previous books, I honestly think she could have done just as well on her own, but since the AI was only used to write the AI character, I suppose it was an interesting experiment.
The audiobook production was excellent, and I enjoyed the dual narration by Avery Caris for Sirena’s point of view and Jonathan Lake for Nex/Xen’s point of view. Both narrators have clear enunciation and good pacing, distinct voices that suit the characters, and the ability to convey the emotions and intensity of the story effectively. This definitely isn’t safe for work or for children, but it was exciting to listen to privately.
I cautiously recommend this book for fans of dark speculative fiction and erotic romance. Note that the book contains kidnapping/human trafficking, violence, assault, swearing, and very explicit sex scenes.
I received a free ARC and an advanced listener’s copy of the audiobook from the author. I volunteered to provide an honest review.
Sirena Bannerman is the half human/half siren daughter of the man who runs the Monster Security Agency. Nex is the Monster Security Agency’s AI, and he becomes obsessed with protecting Sirena, with unexpected results.
This story starts with an interesting mystery about a woman with amnesia who has had a lot of plastic surgery, and as Sirena and Nex investigate what might have happened to her, the situation quickly spirals out of control, becoming a very dangerous and suspenseful adventure with a cruel and powerful adversary. I enjoyed seeing characters from the previous Monster Security Agency books get involved; there are some crazy creatures in this world. There’s also quite a bit of humor to help relieve the intensity.
The author used AI to help write the portions of the story that are from Nex/Xen’s point of view. Based on her previous books, I honestly think she could have done just as well on her own, but since the AI was only used to write the AI character, I suppose it was an interesting experiment.
The audiobook production was excellent, and I enjoyed the dual narration by Avery Caris for Sirena’s point of view and Jonathan Lake for Nex/Xen’s point of view. Both narrators have clear enunciation and good pacing, distinct voices that suit the characters, and the ability to convey the emotions and intensity of the story effectively. This definitely isn’t safe for work or for children, but it was exciting to listen to privately.
I cautiously recommend this book for fans of dark speculative fiction and erotic romance. Note that the book contains kidnapping/human trafficking, violence, assault, swearing, and very explicit sex scenes.
I received a free ARC and an advanced listener’s copy of the audiobook from the author. I volunteered to provide an honest review.
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