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Monster Security Agency #8
Guarded by the Nightmare
No one survives hiring me. Not even her.
I’m a Nightmare, a creature that feeds on fear, and I’m capable of boundless cruelty—which is why my services come at a steep the life of the person who hired me. As such, the only people who hire me on are those brought to me by fate, like Mina, a woman so desperate for revenge that she’s willing to spend her own life to get it.
I don’t usually care why I’m hired. Human affairs don’t matter to me. Food is food, and a job is a job.
Mina’s enemies will get what they deserve—and I’ll get what’s mine.
Her beating heart.
Monster Security Agency is the most elite bodyguard service in the world. These monster bodyguards are lethal, powerful, and determined to protect their clients at all costs. They shouldn't fall in love with their principals, but if they do? Things are bound to explode.
Here come spicy, romantic, and action-packed tales by your favorite paranormal and sci-fi romance Cassie Alexander, Layla Fae, and Cara Wylde. Dive into the world of the Monster Security Agency.
I’m a Nightmare, a creature that feeds on fear, and I’m capable of boundless cruelty—which is why my services come at a steep the life of the person who hired me. As such, the only people who hire me on are those brought to me by fate, like Mina, a woman so desperate for revenge that she’s willing to spend her own life to get it.
I don’t usually care why I’m hired. Human affairs don’t matter to me. Food is food, and a job is a job.
Mina’s enemies will get what they deserve—and I’ll get what’s mine.
Her beating heart.
Monster Security Agency is the most elite bodyguard service in the world. These monster bodyguards are lethal, powerful, and determined to protect their clients at all costs. They shouldn't fall in love with their principals, but if they do? Things are bound to explode.
Here come spicy, romantic, and action-packed tales by your favorite paranormal and sci-fi romance Cassie Alexander, Layla Fae, and Cara Wylde. Dive into the world of the Monster Security Agency.
380 pages, Kindle Edition
Published October 16, 2024
About the author
Cassie Alexander
237 books1,534 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 351 reviews
November 25, 2024
This review may contain mild spoilers.
This is the third book from this author I've read and I'm finding she has a tendency to use certain heavy topics for shock value only and the story ends up feeling lacking.
I enjoy reading dark romance in general because I feel like authors have the opportunity to explore heavy topics and give the story more depth and therefore a certain level of maturity and that's exactly what, unfortunately, this author lacks completely.
The story's main topic of discussion is FMC's hiring the MMC because she wants revenge on the guys that gang r@ped her and tried to kill her best friend for a spiritual sacrifice of some sort. The first problem I find with this is the inconsistency of the story line, the FMC talks from her POV about her being broken and traumatised after everything she went through but after a few chapters she's banging the MMC's brains out without any sort of trouble, this story doesn't depict a SA's victim proper healing journey because apparently everything is fixed with a few bad jokes and some monster 🍆.
Like seriously, there where moments where even the MMC seemed more concerned about FMC's wellbeing than herself.
I don't know if the author's way of making the story more digestible is by making a FMC who seems more focused on throwing bad jokes and laughing at the least funny moments throughout the story to make her more 'quirky' but it ends up feeling so immature and childish I could barely stand her but what finished convincing me to not pick up another book from this author was a frase said by the FMC at the last chapter: “Okay, but, I want you to fuck me till we give our baby brain damage—or, I see god. One of those two.”
Mind you, the FMC is seven months pregnant at this point of the story and she's again throwing the stupidest 'jokes' in the worst possible way and time.
That left a really bad taste on my mouth, it felt unnecessary and it totally took away the only other thing that I enjoyed of the story, after the MMC, which is the pregnancy trope in a monster romance.
Anyways, after all that rant, just beware if you're looking for a story about healing or even overcoming trauma then this isn't it. And prepared for an annoying and childish FMC 🙄, the only positive thing about this book was the MMC who is a shadow daddy that gave us a few good spicy moments and even some heartfelt ones too.
This is the third book from this author I've read and I'm finding she has a tendency to use certain heavy topics for shock value only and the story ends up feeling lacking.
I enjoy reading dark romance in general because I feel like authors have the opportunity to explore heavy topics and give the story more depth and therefore a certain level of maturity and that's exactly what, unfortunately, this author lacks completely.
The story's main topic of discussion is FMC's hiring the MMC because she wants revenge on the guys that gang r@ped her and tried to kill her best friend for a spiritual sacrifice of some sort. The first problem I find with this is the inconsistency of the story line, the FMC talks from her POV about her being broken and traumatised after everything she went through but after a few chapters she's banging the MMC's brains out without any sort of trouble, this story doesn't depict a SA's victim proper healing journey because apparently everything is fixed with a few bad jokes and some monster 🍆.
Like seriously, there where moments where even the MMC seemed more concerned about FMC's wellbeing than herself.
I don't know if the author's way of making the story more digestible is by making a FMC who seems more focused on throwing bad jokes and laughing at the least funny moments throughout the story to make her more 'quirky' but it ends up feeling so immature and childish I could barely stand her but what finished convincing me to not pick up another book from this author was a frase said by the FMC at the last chapter: “Okay, but, I want you to fuck me till we give our baby brain damage—or, I see god. One of those two.”
Mind you, the FMC is seven months pregnant at this point of the story and she's again throwing the stupidest 'jokes' in the worst possible way and time.
That left a really bad taste on my mouth, it felt unnecessary and it totally took away the only other thing that I enjoyed of the story, after the MMC, which is the pregnancy trope in a monster romance.
Anyways, after all that rant, just beware if you're looking for a story about healing or even overcoming trauma then this isn't it. And prepared for an annoying and childish FMC 🙄, the only positive thing about this book was the MMC who is a shadow daddy that gave us a few good spicy moments and even some heartfelt ones too.
January 3, 2025
Awesome and original monster romance!
The following ratings are out of 5:
Romance: 💚🖤❤️💜🩵
Heat/Steam: 🔥🔥🔥🔥
Story/Plot: 📕📗📙📘📔
World building: 🌏🌍🌎🌏🌍
Character development: ☹️☺️😊🥰😍
The heroine: Mina - her and her best friend Ella were at college and drugged and something very bad happened to them and it was done by the members of a fraternity. Ella has been in a coma for six months and Mina has basically died inside when nobody believed her. She wants nothing more than to get revenge against the men and she knows that after doing so, she will probably get the death penalty, so she decides to go about it in a different way. She doesn’t care that she will be killed also, as it will just be an end to her misery and is worth it if she gets her revenge along the way.
The Hero: Sylas (a.k.a. the hourglass killer) - he was once human but that was a very long time ago. He is now a nightmare, a smoke and shadows monster that feeds on fear, terror and other bad emotions and eating the beating hearts of his victims. He was once free to roam about the world feeding on whomever he pleased until the great-grandfather of Royce Bannerman, the owner of the Monster Security Agency, bound him to his line and to the hourglass. Now lives inside the hourglass until it runs out, then he can be hired by someone who comes into the MSA to hire him. He is then bound to that person and can feed from whomever that person tells him to until the sands run out again, at which point he will eat the beating heart out of the person he is bound to. Then he goes back in his hourglass.
The story: Mina did extensive research on the hourglass killer and knows what he does, though she doesn’t know exactly what he is. There are all kinds of monsters in the world that are known by humans, not all is known about each kind. Though she does know after all her research, is that he is the perfect monster for her needs.
This book was so original in a field of paranormal romance that have so many vampire and shifter stories that are just variations on the same or similar themes. I tend to love monster romance for that very reason and this one was even more original than most.
The world building in this book was terrific. The descriptions of what happened to Mina and Ella were done so well in flashbacks or dreams, that I was terrified when it was close to happening. It wasn’t quite what I thought it would be, but the fact that they had been set up for it to happen for six months prior to it that got my emotions all up in arms about it. Not only that, but they made her look and feel like a crazy person after it all went down.
The descriptions of what Mina went through made it much easier to not only stomach the brutal revenge but to know that it was more than well deserved however savage and cruel it would be. The story got better and better as it got more intricate, and the steamy parts were pretty hot as well. I liked both the romance and the revenge story and will definitely be looking into more books by Cassie Alexander. She wrote a few more in this same series, and I wasn’t really interested in those types of monsters, but after reading this book, I think I will try them next.
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The following ratings are out of 5:
Romance: 💚🖤❤️💜🩵
Heat/Steam: 🔥🔥🔥🔥
Story/Plot: 📕📗📙📘📔
World building: 🌏🌍🌎🌏🌍
Character development: ☹️☺️😊🥰😍
The heroine: Mina - her and her best friend Ella were at college and drugged and something very bad happened to them and it was done by the members of a fraternity. Ella has been in a coma for six months and Mina has basically died inside when nobody believed her. She wants nothing more than to get revenge against the men and she knows that after doing so, she will probably get the death penalty, so she decides to go about it in a different way. She doesn’t care that she will be killed also, as it will just be an end to her misery and is worth it if she gets her revenge along the way.
The Hero: Sylas (a.k.a. the hourglass killer) - he was once human but that was a very long time ago. He is now a nightmare, a smoke and shadows monster that feeds on fear, terror and other bad emotions and eating the beating hearts of his victims. He was once free to roam about the world feeding on whomever he pleased until the great-grandfather of Royce Bannerman, the owner of the Monster Security Agency, bound him to his line and to the hourglass. Now lives inside the hourglass until it runs out, then he can be hired by someone who comes into the MSA to hire him. He is then bound to that person and can feed from whomever that person tells him to until the sands run out again, at which point he will eat the beating heart out of the person he is bound to. Then he goes back in his hourglass.
The story: Mina did extensive research on the hourglass killer and knows what he does, though she doesn’t know exactly what he is. There are all kinds of monsters in the world that are known by humans, not all is known about each kind. Though she does know after all her research, is that he is the perfect monster for her needs.
“Oh, tsk, Royce. I don’t sleep. I only make others sleep—sleep, and dream of me.” It was a portion of the quote inscribed on a swooping portion of my hourglass’s golden frame. And on the inside of that inscription, in a place only I could see, was the phrase: Time gives fate a reason. Fate gives time a point.
“Because sometimes—very rarely—people did get to hire me.
And on those occasions I would get to not only follow them for a time, but do their bidding, and I would be permitted to not just feed on fear and hate and terror, but allowed to cause it.
Personally.
Violently.
Up until their sand ran out and I finally slaughtered them.”
“I rolled the sleeve of my scratchy sweater up, to find that somehow I’d been branded with an hourglass, just like the images I’d seen on old coroners reports in my research—the sign of the Hourglass Killer.
But what those photos hadn’t shown was the inside of the brand, where the hourglass’s sand was.
It was tattooed red . . . and the ink was moving.
Draining from one chamber into the next, ever so slowly.”
“And you can’t tell me any of your other names?” Maybe they’d have a clue for me as to what he actually was, other than a death-dealing serial-killing smoke-monster that’d apparently been alive for a century.
This book was so original in a field of paranormal romance that have so many vampire and shifter stories that are just variations on the same or similar themes. I tend to love monster romance for that very reason and this one was even more original than most.
The world building in this book was terrific. The descriptions of what happened to Mina and Ella were done so well in flashbacks or dreams, that I was terrified when it was close to happening. It wasn’t quite what I thought it would be, but the fact that they had been set up for it to happen for six months prior to it that got my emotions all up in arms about it. Not only that, but they made her look and feel like a crazy person after it all went down.
The descriptions of what Mina went through made it much easier to not only stomach the brutal revenge but to know that it was more than well deserved however savage and cruel it would be. The story got better and better as it got more intricate, and the steamy parts were pretty hot as well. I liked both the romance and the revenge story and will definitely be looking into more books by Cassie Alexander. She wrote a few more in this same series, and I wasn’t really interested in those types of monsters, but after reading this book, I think I will try them next.
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October 17, 2024
I’m trying to think of a way to react that would do justice to this book.
The whole premise of the story is very creative. Sylas, the MMC, is a Nightmare: a dark, diaphanous being that feeds on fear and takes joy (as much as a soulless being can) in killing. Mina, the MMC, is living with some extreme trauma after being assaulted multiple times by members of her college fraternity. Mina isn’t really even living at this point, she’s just existing after being brutalized; her friend , Ella, was also a victim of the fraternity’s strange antics and she has been hospitalized, comatose for the last six months. Mina is angry, and she wants revenge.
Mina hires Sylas to help her go after the group of men who attacked her. In doing so, she trades her life as payment to morally black Sylas in return for the lives he’s about to take. Their revenge effort starts how you’d probably think it would: Sylas taking joy in snuffing out the attackers one by one. But things take a turn: maybe Sylas isn’t so bad? Mina thinks he’s actually kind of funny. And Sylas starts to enjoy putting a smile back on Mina’s face. But what of their bargain: her life in exchange for the taking of theirs?
There’s all kinds of other things going on in the story — strange magic, evil from a cursed Egyptian object, spicy time between the two main characters, a protective instinct going into overdrive, the promise of new life, and the ultimate act of love: sacrificing yourself for those you love.
Some of the themes may be triggering, so take heed of CWs. This was at turns sad, dark, depressing, witty, funny, hopeful, maybe a little unhinged (but not in a bad way), and ultimately, a little beautiful.
The whole premise of the story is very creative. Sylas, the MMC, is a Nightmare: a dark, diaphanous being that feeds on fear and takes joy (as much as a soulless being can) in killing. Mina, the MMC, is living with some extreme trauma after being assaulted multiple times by members of her college fraternity. Mina isn’t really even living at this point, she’s just existing after being brutalized; her friend , Ella, was also a victim of the fraternity’s strange antics and she has been hospitalized, comatose for the last six months. Mina is angry, and she wants revenge.
Mina hires Sylas to help her go after the group of men who attacked her. In doing so, she trades her life as payment to morally black Sylas in return for the lives he’s about to take. Their revenge effort starts how you’d probably think it would: Sylas taking joy in snuffing out the attackers one by one. But things take a turn: maybe Sylas isn’t so bad? Mina thinks he’s actually kind of funny. And Sylas starts to enjoy putting a smile back on Mina’s face. But what of their bargain: her life in exchange for the taking of theirs?
There’s all kinds of other things going on in the story — strange magic, evil from a cursed Egyptian object, spicy time between the two main characters, a protective instinct going into overdrive, the promise of new life, and the ultimate act of love: sacrificing yourself for those you love.
Some of the themes may be triggering, so take heed of CWs. This was at turns sad, dark, depressing, witty, funny, hopeful, maybe a little unhinged (but not in a bad way), and ultimately, a little beautiful.
November 19, 2024
I liked a lot of things about this book. I feel like the characters were mostly enjoyable, the writing was honestly really well done, and the villains were repulsive and deserving of everything that happened to them.
HOWEVER!!!
I was told before going into this to not think TOO much about the world building aspect of this and after reading it I CAN confirm that you really won’t get a feel for how things work.
The fates idea was so cool and the descriptions of how beautiful they were was so fun to read.. but the explanations on how it worked were honestly so lacking.
The romance was BEAUTIFUL at the end… except for the fact that they had sex like once or twice and suddenly they’re boyfriend and girlfriend?
Not only was the moment she called him her boyfriend a little immature and childish sounding, it also fell flat because… since when girl?
Overall, it was a relatively decent book and if not for this comment alone I would’ve wholeheartedly given it three/ four stars.
I enjoyed myself and loved the smut, I got teary eyed at some parts, was confused at others, but it was fun!!
Until.
Jesus Christ until.
I’m not sure WHAT the author was thinking or what in her right mind could have possibly made her think this was in any way okay to say and I’m APPALLED nobody has said anything about it yet but here’s a DIRECT quote that took the book down an entire star (although for the overall quality of the book it’s still just remained a two)
“Okay, but, I want you to fuck me till we give our baby brain damage—or, I see god. One of those two.”
What
The
Fuck
Not only is that INCREDIBLY insensitive.. it’s not at all funny? Because why??
So mad about this! It ruined the whole ending for me lol
HOWEVER!!!
I was told before going into this to not think TOO much about the world building aspect of this and after reading it I CAN confirm that you really won’t get a feel for how things work.
The fates idea was so cool and the descriptions of how beautiful they were was so fun to read.. but the explanations on how it worked were honestly so lacking.
The romance was BEAUTIFUL at the end… except for the fact that they had sex like once or twice and suddenly they’re boyfriend and girlfriend?
Not only was the moment she called him her boyfriend a little immature and childish sounding, it also fell flat because… since when girl?
Overall, it was a relatively decent book and if not for this comment alone I would’ve wholeheartedly given it three/ four stars.
I enjoyed myself and loved the smut, I got teary eyed at some parts, was confused at others, but it was fun!!
Until.
Jesus Christ until.
I’m not sure WHAT the author was thinking or what in her right mind could have possibly made her think this was in any way okay to say and I’m APPALLED nobody has said anything about it yet but here’s a DIRECT quote that took the book down an entire star (although for the overall quality of the book it’s still just remained a two)
“Okay, but, I want you to fuck me till we give our baby brain damage—or, I see god. One of those two.”
What
The
Fuck
Not only is that INCREDIBLY insensitive.. it’s not at all funny? Because why??
So mad about this! It ruined the whole ending for me lol
September 18, 2025
This story definitely has some much darker elements incorporated here, which is surprising as most of the books I have read in this universe manage to tap very lightly into past traumas. What did not work quite well here for me was the lack of healing process for the FMC after her rather horrendous experiences.
Sylas was a gem, a nightmare who brings havoc and destruction. He was a sweetheart to the main heroine, despite their less than traditional romance.
All in all, the story did have interesting elements and I did enjoy it.
Sylas was a gem, a nightmare who brings havoc and destruction. He was a sweetheart to the main heroine, despite their less than traditional romance.
All in all, the story did have interesting elements and I did enjoy it.
May 2, 2025
Love Silas and the world building in this one was really interesting. Also great narration (audiobook)!
November 5, 2024
Terrible! Absolutely terrible!
And not just compared to the others in this series this either, but as a stand alone it was bad. Multiple times sentences didn’t make sense (random sentences, but also entire scenes - chase scenes - which completely ruin the mood - it’s impossible to be scared if you don’t actually know what’s happening), the characters weren’t engaging or stimulating enough for me to care about them, and the flashbacks went on far too much.
Alexander doesn’t have the writing skills for whatever this attempt was. She was trying to create some magical fantasy, and it seemed like a good idea, but either wasn’t well thought out enough or so poorly written that it didn’t translate on paper. As a reader I got a glimpse of whatever Alexander was trying to sell me, but that was all. She should have stuck to the sexy romance because whatever she was trying to do here didn’t work.
And not just compared to the others in this series this either, but as a stand alone it was bad. Multiple times sentences didn’t make sense (random sentences, but also entire scenes - chase scenes - which completely ruin the mood - it’s impossible to be scared if you don’t actually know what’s happening), the characters weren’t engaging or stimulating enough for me to care about them, and the flashbacks went on far too much.
Alexander doesn’t have the writing skills for whatever this attempt was. She was trying to create some magical fantasy, and it seemed like a good idea, but either wasn’t well thought out enough or so poorly written that it didn’t translate on paper. As a reader I got a glimpse of whatever Alexander was trying to sell me, but that was all. She should have stuck to the sexy romance because whatever she was trying to do here didn’t work.
June 6, 2026
Guarded by the Nightmare is a quick read with very dark themes. This is my first book by Cassie Alexander, but book 8 in her Monster Security Agency series.
Trigger Warnings: SA (off page), gore
The FMC, Mina, goes through awful life events. She suffers trauma and SA, no one believes her, and she feels she has no choice but to “hire” the Nightmare to enact her revenge. She is a very inconsistent character in the story. She is at times bloodthirsty, horny, loving and humorous, grossed out by events, intrigued by events, brave, terrified, having panic attacks, and then coining the term murder-buddies and joyfully strategizing murders. I think her behaviors were intentional by the author, but made it challenging for me to fully connect with the FMC.
Sylas, the MMC, is an elemental fate and time manipulating genie-esque creature made of shadows, called the Nightmare. He was once a human, but I learned very little about him overall, so I don’t know how or why he became the Nightmare. I liked his humor and protectiveness.
The plot was medium paced. I was entertained and the dialogue was smooth. I liked the flow of the narrative, but the version I read (physical paperback) has a large amount of sentence structural issues/typos.
The world building was lacking and confusing. (Note: this is book 8 in a series and the only book of the series I’ve read. It’s possible some of this could be answered within the series). The fate ties and time stones needed more clarity in the story. We do not find out how or why Sylas was contained by these stones. We don’t learn much about the world, types of monsters in it, political influences, or other “normal” human/monster interactions.
This book has spice, 🌶️🌶️🌶️
Overall, this book is dark, gory, and spicy. I am not sure I will continue with the series at this time.
Trigger Warnings: SA (off page), gore
The FMC, Mina, goes through awful life events. She suffers trauma and SA, no one believes her, and she feels she has no choice but to “hire” the Nightmare to enact her revenge. She is a very inconsistent character in the story. She is at times bloodthirsty, horny, loving and humorous, grossed out by events, intrigued by events, brave, terrified, having panic attacks, and then coining the term murder-buddies and joyfully strategizing murders. I think her behaviors were intentional by the author, but made it challenging for me to fully connect with the FMC.
Sylas, the MMC, is an elemental fate and time manipulating genie-esque creature made of shadows, called the Nightmare. He was once a human, but I learned very little about him overall, so I don’t know how or why he became the Nightmare. I liked his humor and protectiveness.
The plot was medium paced. I was entertained and the dialogue was smooth. I liked the flow of the narrative, but the version I read (physical paperback) has a large amount of sentence structural issues/typos.
The world building was lacking and confusing. (Note: this is book 8 in a series and the only book of the series I’ve read. It’s possible some of this could be answered within the series). The fate ties and time stones needed more clarity in the story. We do not find out how or why Sylas was contained by these stones. We don’t learn much about the world, types of monsters in it, political influences, or other “normal” human/monster interactions.
This book has spice, 🌶️🌶️🌶️
Overall, this book is dark, gory, and spicy. I am not sure I will continue with the series at this time.
January 3, 2025
I don't know why this book has such a high rating...it was poorly written, shallow, and just not good. If I could've DNF'd it, I would have. But every time I DNF a book, it stays in my brain and takes up space that could be used for watching commercials or tiktok reels. And I did not want this in my brain. But I also wish I could get my time back... Monster kink aside, the characters had zero depth. I couldn't muster an ounce of care for the MFC's trauma that initiates this story...it was just handled with so little depth of care. The author kind of tries at the beginning of the novel, but rather than having the characters become more interesting/in-depth, they get...more and more shallow? Save yourself and don't bother with it, unless you're hear for kinky weird monster sex scenes. If that's your tea, then just skip the lackluster story and go straight for the kink.
May 8, 2025
3.75✨ (rounded to 4 for GR)
2.5🌶️
Calling all shadow daddy monster lovers, I think you're gonna want to see this!
🖤enemies-to-lovers (in the sense that the MMC literally wants to kill the FMC in the beginning, with her knowledge of course)
🖤slow burn
🖤MMC eventually becomes very protective
🖤MMC is unrepentantly 'evil' (truly he's a villain, just not to the FMC by the end)
🖤banter
🖤broken FMC bent on revenge
Guarded by the Nightmare by Cassie Alexander is the eighth installment in the Monster Security Agency series, and it breaks away from the usually bodyguard formula just enough to give it a little edge, a little...spice.
Mina, our FMC, is a woman desperate for revenge against the men that severely hurt her best friend in a way she may not come back from. It's a cause she's willing to die for, as made evident by her seeking assistance not from Monster Security Agency itself, but rather a dark entity it has control over: The Nightmare (aka Sylas). And he agrees to the deal. The price? He feeds on her fear, her bitter emotions, until she dies, forever connected to him.
Sylas hadn't always been a Nightmare; he was human once, long ago, so long he can't even grasp the idea of remembering it. Now his essence burns for darkness, feeding on fear, terror, sadness, anger while he's not under the control of MSA. His being is tied to an ancient hourglass, and he's only allowed in this world for how long the sand takes to drop.
Sylas is truly a monster, in a lot of senses of the word. I love how he's described throughout the book, I could visualize him very clearly. But he's a villain, villain. He's done some dark, dark things to humanity in the past and he's not sorry. He feels no remorse, he thinks he can barely feel at all. These deeds and how they're described and Sylas' reaction to them is somewhat off-putting, I'll admit, and I think this very fact will alienate some readers. But this is a true dark monster romance, as unrepentant in that as Sylas is in his violence.
I would say Sylas and Mina's relationship was somewhat slow burn, because they started so low on the scale, with him getting to kill her as part of the contract after all. But their forced proximity also forced them to have conversations, and grow in each other's company. I would've liked to have seen a teensy more development before their relationship turned physical. But oh boy, when it did turn physical??? Monster romances will ALWAYS be one of the GOATs, and this creative shadow spice only cements that fact.
Aside from some odd word choices here and there (I found the whole "girlfriend" and "boyfriend" labels out of place), this was a solid entry to this series and a great monster romance overall. I thought the small deviation to the classic hiring-an-MSA-bodyguard was a win this case, as it gave this book a slightly different narrative, which added some variety. Still managing to be fresh as the eighth book in a series is pretty awesome. I know they're by differing authors, but still awesome. Sylas is a definitely-not-for-all monster MMC that has an unexpectedly dry sense of humor to go along with his murderous tendencies, which I think is needed to bring the broken Mina out of the pit of despair she's in.
There's been some serious gems in this series overall, and I can't wait to see what's next!
2.5🌶️
Calling all shadow daddy monster lovers, I think you're gonna want to see this!
🖤enemies-to-lovers (in the sense that the MMC literally wants to kill the FMC in the beginning, with her knowledge of course)
🖤slow burn
🖤MMC eventually becomes very protective
🖤MMC is unrepentantly 'evil' (truly he's a villain, just not to the FMC by the end)
🖤banter
🖤broken FMC bent on revenge
Guarded by the Nightmare by Cassie Alexander is the eighth installment in the Monster Security Agency series, and it breaks away from the usually bodyguard formula just enough to give it a little edge, a little...spice.
Mina, our FMC, is a woman desperate for revenge against the men that severely hurt her best friend in a way she may not come back from. It's a cause she's willing to die for, as made evident by her seeking assistance not from Monster Security Agency itself, but rather a dark entity it has control over: The Nightmare (aka Sylas). And he agrees to the deal. The price? He feeds on her fear, her bitter emotions, until she dies, forever connected to him.
Sylas hadn't always been a Nightmare; he was human once, long ago, so long he can't even grasp the idea of remembering it. Now his essence burns for darkness, feeding on fear, terror, sadness, anger while he's not under the control of MSA. His being is tied to an ancient hourglass, and he's only allowed in this world for how long the sand takes to drop.
Sylas is truly a monster, in a lot of senses of the word. I love how he's described throughout the book, I could visualize him very clearly. But he's a villain, villain. He's done some dark, dark things to humanity in the past and he's not sorry. He feels no remorse, he thinks he can barely feel at all. These deeds and how they're described and Sylas' reaction to them is somewhat off-putting, I'll admit, and I think this very fact will alienate some readers. But this is a true dark monster romance, as unrepentant in that as Sylas is in his violence.
I would say Sylas and Mina's relationship was somewhat slow burn, because they started so low on the scale, with him getting to kill her as part of the contract after all. But their forced proximity also forced them to have conversations, and grow in each other's company. I would've liked to have seen a teensy more development before their relationship turned physical. But oh boy, when it did turn physical??? Monster romances will ALWAYS be one of the GOATs, and this creative shadow spice only cements that fact.
Aside from some odd word choices here and there (I found the whole "girlfriend" and "boyfriend" labels out of place), this was a solid entry to this series and a great monster romance overall. I thought the small deviation to the classic hiring-an-MSA-bodyguard was a win this case, as it gave this book a slightly different narrative, which added some variety. Still managing to be fresh as the eighth book in a series is pretty awesome. I know they're by differing authors, but still awesome. Sylas is a definitely-not-for-all monster MMC that has an unexpectedly dry sense of humor to go along with his murderous tendencies, which I think is needed to bring the broken Mina out of the pit of despair she's in.
There's been some serious gems in this series overall, and I can't wait to see what's next!
April 12, 2025
Ok I am sorry if this was a great book to you but I have to be honest I suffered through it. I hated the main female character she was insufferable and just a whore. She kept saying she had a high sex drive but that’s no excuse for having sex with anything that walks basically. The main male character was okay but I didn’t really like him either he kept saying how bad and evil he was and how he didn’t care and yet everything he did showed that he cared even before they both started catching feelings. They were both just lonely that’s the only reason their romance even happened and it wasn’t even done right in my opinion. The main female character treated her best friend like shit btw even though she didn’t think she did in her opinion like she was classic mean girl but didn’t know it I got a lot of Jennifer’s body vibes from their “friendship” I don’t care I just did. Also the whole frat boy creepy magic cult thing as the driving plot I mean seriously that’s the best you got it was terrible I’m sorry I liked nothing about it. Don’t even go there with the time baby thing in the end like I am so done.
Like now I literally need a really good romance to get this out of my head.
Like now I literally need a really good romance to get this out of my head.
This entire review has been hidden because of spoilers.
October 17, 2024
Guarded by the Nightmare by Cassie Alexander is the deepest, most moving, most satisfying monster fic I’ve ever read. No, really.
Humans can hire the Nightmare Sylas to kill people for them, but it comes at a cost: when he has done your bidding he will rip your beating heart from your chest and eat it.
Mina is that desperate. Any kind of human justice has failed her in the wake of the SA of her and the catastrophic injury of Ella, her best friend. Mina asks Sylas to kill the members of the college fraternity that assaulted her and Ella, knowing that she is paying with her life.
You watch Mina and Sylas find each other knowing that he must utterly destroy her within the week. Holy crap it’s heartbreaking.
I’m in awe of what Alexander has accomplished here.
Trigger warnings: repeated flashbacks of events leading to her SA, sui¢ide ideation, completely amoral MMC, multiple graphic murd3rs.
🖤🖤🖤
Humans can hire the Nightmare Sylas to kill people for them, but it comes at a cost: when he has done your bidding he will rip your beating heart from your chest and eat it.
Mina is that desperate. Any kind of human justice has failed her in the wake of the SA of her and the catastrophic injury of Ella, her best friend. Mina asks Sylas to kill the members of the college fraternity that assaulted her and Ella, knowing that she is paying with her life.
You watch Mina and Sylas find each other knowing that he must utterly destroy her within the week. Holy crap it’s heartbreaking.
I’m in awe of what Alexander has accomplished here.
Trigger warnings: repeated flashbacks of events leading to her SA, sui¢ide ideation, completely amoral MMC, multiple graphic murd3rs.
🖤🖤🖤
July 9, 2025
Not sure what I even just read but god bless.
April 30, 2025
She wasn't scared of death. She was scared of being alive and finding out that life had no meaning. But time gave fate reason. And fate gave time a point.
This story was crazy good. Like the whole monster romance thing was center stage but the circumstances and plot!!! What a story. I was reading as quickly as possible to find out what was going to happen. Mina hires this monster that no one else hires because of the payment. But she really doesn't care. She will do anything to save her friend Ella and for the men who hurt them pay. But fate has other plans and this isn't just about a group of college boys. It's much bigger and much darker and full of bad magic. I still have some questions about the magic and how it was so similar to Sylas's magic. It's answered, somewhat, but this story alone could have so many more spinoffs or parts and all of them would be good. Once you get over the whole monster romance thing it's easier to handle. Sylas is not a good being, he's not even nice, he is a true monster. But for her he is willing to change and adapt in order to keep her so it works out.
This story was crazy good. Like the whole monster romance thing was center stage but the circumstances and plot!!! What a story. I was reading as quickly as possible to find out what was going to happen. Mina hires this monster that no one else hires because of the payment. But she really doesn't care. She will do anything to save her friend Ella and for the men who hurt them pay. But fate has other plans and this isn't just about a group of college boys. It's much bigger and much darker and full of bad magic. I still have some questions about the magic and how it was so similar to Sylas's magic. It's answered, somewhat, but this story alone could have so many more spinoffs or parts and all of them would be good. Once you get over the whole monster romance thing it's easier to handle. Sylas is not a good being, he's not even nice, he is a true monster. But for her he is willing to change and adapt in order to keep her so it works out.
October 17, 2024
Love Cassie’s books and this one was no different. There is just something intrinsically lovable about her monsters. ❤️❤️
What makes Sylas so great is that he is just unapologetically himself. I’ve noticed a lot of authors try to make the villian ‘less monstrous’ or make them ‘better’ for the sake of the FMC and character growth. Sylas stays his lovely self from page one all the way to the end and our FMC loves him for who he is and doesn’t expect him to be anything else. This is not to say he doesn’t have a great character arch in his own way.
The same can be said for our FMC though. She has had a rough couple years and has been irreparably broken. And even though Sylas is technically a bad guy he is so dang supportive of the leading lady. Just gotta love a man that loves his woman through all her dumpster fire-ness and her homicidal tendencies 😏
Overall was a great read. If you love a good monster romance this will right up your alley. Because Sylas truly is monstrous, but gosh dang are his powers and abilities the shiz-nit! He’s awesome! Seriously!
What makes Sylas so great is that he is just unapologetically himself. I’ve noticed a lot of authors try to make the villian ‘less monstrous’ or make them ‘better’ for the sake of the FMC and character growth. Sylas stays his lovely self from page one all the way to the end and our FMC loves him for who he is and doesn’t expect him to be anything else. This is not to say he doesn’t have a great character arch in his own way.
The same can be said for our FMC though. She has had a rough couple years and has been irreparably broken. And even though Sylas is technically a bad guy he is so dang supportive of the leading lady. Just gotta love a man that loves his woman through all her dumpster fire-ness and her homicidal tendencies 😏
Overall was a great read. If you love a good monster romance this will right up your alley. Because Sylas truly is monstrous, but gosh dang are his powers and abilities the shiz-nit! He’s awesome! Seriously!
October 17, 2024
Is this book dark? This guy is made of dark. Dark smoke and danger. Sylas is another excellent monster created by Cassie. And Mina is a deeply damaged woman who can still be fierce and devoted. I’ve enjoyed each of the books from the Monster Security Agency that I have read, and this one is no exception. Twisty, intriguing, interesting magic, sass, darkness (Did I already mention that it’s dark?), and hot enough to start a forest fire. Mind the trigger warnings if you need to. But if you read it, this story will take you on one hell of a ride. The narration by Jonathan Lake and Avery Caris is also outstanding. Perfect for the characters. Honestly, Jonathan’s voice sounds a bit like smoke itself. Well done!
October 14, 2024
4.75 ☆
Cassie has done it once again! She's made me fall in love with someone who doesn't exist. Gosh! This story could be triggering for some people, so please read the TW before reading. The storyline alternates between present and past with dual POVs. I highly enjoyed this story.
The audiobook is great. The narrator did a great job telling the story, and it was easy to listen to and understand what they were saying.
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Thank you, Cassie for the Ebook and audiobook in exchange for my honest review.
Cassie has done it once again! She's made me fall in love with someone who doesn't exist. Gosh! This story could be triggering for some people, so please read the TW before reading. The storyline alternates between present and past with dual POVs. I highly enjoyed this story.
The audiobook is great. The narrator did a great job telling the story, and it was easy to listen to and understand what they were saying.
-
Thank you, Cassie for the Ebook and audiobook in exchange for my honest review.
October 15, 2024
I never would have thought that I'd fall in love with a nightmare, but damn.
Cassie outdid herself again and I'm questioning my sanity after reading and falling for that another monster.
I wasn't sure what to expect but I was not disappointed and was reminded as to why I always wait for Cassie's newsletters😍
Cassie outdid herself again and I'm questioning my sanity after reading and falling for that another monster.
I wasn't sure what to expect but I was not disappointed and was reminded as to why I always wait for Cassie's newsletters😍
November 5, 2024
This was not at all what I was expecting and I enjoyed every minute. It was dark and tragic but also incredibly heartfelt... for being a monster romance 😂😭
Damn.
Damn.
September 2, 2025
Great story, not just monster smut.
Bit of a slow burn but the plot made me ok with it.
Revenge, mystery, gore… I enjoyed it!
Bit of a slow burn but the plot made me ok with it.
Revenge, mystery, gore… I enjoyed it!
August 11, 2026
4.5 stars.
Wow. That was violent AND satisfying.
I'm not usually one for revenge themes but vengeance was needed. And gotten.
This is definitely on the darker side.
Wow. That was violent AND satisfying.
I'm not usually one for revenge themes but vengeance was needed. And gotten.
This is definitely on the darker side.
October 21, 2024
3 solid stars. LOOK. 👀 This book was actually pretty interesting BUT....and I do not say this lightly, this was very DARK. Like serial killer, creepy kinda dark. IDK, it was just a little over the line for me and I do enjoy me some dark romance.
I found the threads of fate KINDA cool but also just a little hard to understand, maybe? Like it was too much. Also, Mina grossed me out a little with how sexually active she was (before the trauma). I was rooting for her revenge on the horrible men on her behalf, but just her overall persona didn't do it for me.
Also I wished there was more from/about Sylas....I get that he was reawakening as something new but I would have like MORE from him/about him etc.
ANYHOO-like I said, this had some quite interesting points and was in fact, well written 🙌🏻 but also it was just a whole lot. ⚖️
Villains: 👿👿👿omg! the villains were just deserving of the horrors Sylas could dish out.
Spice: 🌶️🌶️🌶️ was a decent albeit, a lil strange. But I mean, we ARE reading about monster romance sooooo there was still a lot to work with there.
I found the threads of fate KINDA cool but also just a little hard to understand, maybe? Like it was too much. Also, Mina grossed me out a little with how sexually active she was (before the trauma). I was rooting for her revenge on the horrible men on her behalf, but just her overall persona didn't do it for me.
Also I wished there was more from/about Sylas....I get that he was reawakening as something new but I would have like MORE from him/about him etc.
ANYHOO-like I said, this had some quite interesting points and was in fact, well written 🙌🏻 but also it was just a whole lot. ⚖️
Villains: 👿👿👿omg! the villains were just deserving of the horrors Sylas could dish out.
Spice: 🌶️🌶️🌶️ was a decent albeit, a lil strange. But I mean, we ARE reading about monster romance sooooo there was still a lot to work with there.
October 10, 2024
I couldn’t have loved this book more. This is actually my favorite from this author, and I think tied for my favorite in the series. I really like the depth of the characters, especially the FMC. Definitely got to be aware of that. The MC is a morally black character, and there are trigger warnings for this book. Don’t let the morally black nature of this nightmare fool you he secretly just a big old cinnamon roll, wanting to love his woman.
And when it comes to spice, I don’t know what more you could ask for. this nightmare, asking for consent was hotter then a volcano on the sun. if pressed, I do have a tiny little gripe. There are definitely a couple of moments in the book where dialogue and setting kind of get confusing. Definitely think that it was more of an editing problem than a content problem. But still a really great book.
And when it comes to spice, I don’t know what more you could ask for. this nightmare, asking for consent was hotter then a volcano on the sun. if pressed, I do have a tiny little gripe. There are definitely a couple of moments in the book where dialogue and setting kind of get confusing. Definitely think that it was more of an editing problem than a content problem. But still a really great book.
This entire review has been hidden because of spoilers.
October 22, 2024
“How lovely to meet you, Mina. I can’t wait to eat your beating heart.”
If you can’t get a man who’ll sacrifice everything for you, kisses you with unlimited mouths on all the right places, stops time just to be with you longer, don’t despair. He’s waiting for you in this book.
No words will do this book justice. What a wonderful creative brain does @cassie have.
Who would have guessed Nightmares could be so desirable.
The romance/plot and smut all perfect.
5⭐️
That being said this is a dark book so do check your triggers.
If you can’t get a man who’ll sacrifice everything for you, kisses you with unlimited mouths on all the right places, stops time just to be with you longer, don’t despair. He’s waiting for you in this book.
No words will do this book justice. What a wonderful creative brain does @cassie have.
Who would have guessed Nightmares could be so desirable.
The romance/plot and smut all perfect.
5⭐️
That being said this is a dark book so do check your triggers.
February 20, 2025
Was not for me, and the writing style was frustrating
October 17, 2024
For full transparency I did receive an arc of this book 😊
In Guarded by the Nightmare Mina is determined to get justice for her friend and herself so she seeks out Silas, a nightmare, to make a deal. Silas is more than willing to bargain with her as he gets to feed on her enemies with the goal of eventually feeding on Mina. As we follow Mina and Silas we slowly uncover the night that everything happened and what lead Mina to seek out his services.
I loved this book and enjoyed the audiobook narration. It’s a great story of revenge, friendship, and monster smut lol. We also get a cameo from Nine the mmc from Guarded by the Spider.
Spice level: 🌶️🌶️🌶️🌶️
He is made up of shadows and can summon multiple 🍆 s
Dual POVs
Touch her and die
On page violence
Off page SA
Please check TWs, they can be found at the beginning of the book.
In Guarded by the Nightmare Mina is determined to get justice for her friend and herself so she seeks out Silas, a nightmare, to make a deal. Silas is more than willing to bargain with her as he gets to feed on her enemies with the goal of eventually feeding on Mina. As we follow Mina and Silas we slowly uncover the night that everything happened and what lead Mina to seek out his services.
I loved this book and enjoyed the audiobook narration. It’s a great story of revenge, friendship, and monster smut lol. We also get a cameo from Nine the mmc from Guarded by the Spider.
Spice level: 🌶️🌶️🌶️🌶️
He is made up of shadows and can summon multiple 🍆 s
Dual POVs
Touch her and die
On page violence
Off page SA
Please check TWs, they can be found at the beginning of the book.
November 22, 2024
This was really different and I sort of loved it. FMC hires a monster to get revenge on men that wronged her, on the proviso that he gets to kill her at the end of the week. The story plays out in two timelines, the current one between FMC and MMC, and the past storyline of what happened to her.
This was dark, twisty, wonderfully weird and really engaging with some dark comedy. I wanted to know what happened next and I was rooting for the FMC so hard. The romance felt almost tangential to the main plot to begin with, and there isn't any attraction beyond “she's objectively pretty” until at least halfway through. So then it did feel a little rushed when they exchanged “I love yous” Shortly after, but with these two the whole relationship was so intense that it worked anyway
do check trigger warnings as they're quite extensive including violence, sexual assault (in the past) and murder
This was dark, twisty, wonderfully weird and really engaging with some dark comedy. I wanted to know what happened next and I was rooting for the FMC so hard. The romance felt almost tangential to the main plot to begin with, and there isn't any attraction beyond “she's objectively pretty” until at least halfway through. So then it did feel a little rushed when they exchanged “I love yous” Shortly after, but with these two the whole relationship was so intense that it worked anyway
do check trigger warnings as they're quite extensive including violence, sexual assault (in the past) and murder
August 27, 2025
Mina hires Sylas from the Monster Security Agency to exact revenge on the men that SA’d her and her friend Ella. Sylas is a “nightmare”, a creature who feeds off fear. The price of Sylas’ help is the life of the person hiring him, which Mina happily agrees to pay. I absolutely loved this audiobook. It’s super dark and gory, but I love stories of feminine rage and revenge. And I love how Mina and Sylas’ relationship develops. The spice is different as Sylas being a non-corporeal being can make himself any shape, even turning a finger into a tongue. I don’t know what this says about me that I enjoyed it, but here we are. Also, narrator Jonathan Lake is amazing. With that voice, I could listen to him talk about anything. This is my second book by Cassie Alexander, also a 5-star, and definitely won’t be my last.
“Time gives fate a reason. Fate gives time a point.”
“Time gives fate a reason. Fate gives time a point.”
October 14, 2024
For not having been in a reading mood for the last several months, this book was the PERFECT intro back into the monster romance genre!! Welcome to the most evil, and delicious story featuring a nightmare shadow demon with no concept of human morals and a "ready to die for the cause" female with nothing to lose (except her life!)
What I Loved!
♡ The FMC!!! I don't connect with FMCs very often but Mina was witty, snarky, and brave
♡ The plot knew when to be serious, and when to pull you from the existential thoughts and be funny and lighthearted, a perfect balance
♡ Smoke daddy Sylas had his own flaws, as he was once human, and seeing his vulnerability despite being an all powerful nightmare demon was refreshing
What I Didn't?
◇ Honestly, it was hard to find things I disliked as I read. My only mild concern was in my ability to visualize some of Sylas's characteristics during spicy scenes especially, which pulled me out of the immersion. Other than that I have no qualms.
What I Loved!
♡ The FMC!!! I don't connect with FMCs very often but Mina was witty, snarky, and brave
♡ The plot knew when to be serious, and when to pull you from the existential thoughts and be funny and lighthearted, a perfect balance
♡ Smoke daddy Sylas had his own flaws, as he was once human, and seeing his vulnerability despite being an all powerful nightmare demon was refreshing
What I Didn't?
◇ Honestly, it was hard to find things I disliked as I read. My only mild concern was in my ability to visualize some of Sylas's characteristics during spicy scenes especially, which pulled me out of the immersion. Other than that I have no qualms.
October 16, 2024
“Was god handsome when you met him? Because if he was, I’ll totally fight him”. - Sylas
This is easily one of my favorite books of the year! Sylas is sarcastic and murderous and it takes him time to develop feelings for Mina during their time together. Mina is broken and also very determined to get justice for what happened to her and her friend. She hires him knowing he will kill her in the end, but she doesn’t want anything to happen to anyone else.
Their relationship develops so nicely, and it doesn’t feel forced. Sylas is hilarious as he just doesn’t understand some things and others he is just very sarcastic.
The spice was so good in this book. I don’t want to ruin it for you, but he is a SHADOW and can change his body AT WILL so imagine what that could look like 😉
This is easily one of my favorite books of the year! Sylas is sarcastic and murderous and it takes him time to develop feelings for Mina during their time together. Mina is broken and also very determined to get justice for what happened to her and her friend. She hires him knowing he will kill her in the end, but she doesn’t want anything to happen to anyone else.
Their relationship develops so nicely, and it doesn’t feel forced. Sylas is hilarious as he just doesn’t understand some things and others he is just very sarcastic.
The spice was so good in this book. I don’t want to ruin it for you, but he is a SHADOW and can change his body AT WILL so imagine what that could look like 😉
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