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I.S.S.

Mating Monsters

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My monsters had found me… and they weren’t letting me go.

The institute, also known as ISS, housed the most terrifying nightmares that existed in this world… but the true monster was the one that tortured me day in and day out. The one that had made me feel worthless and question if I could even call myself a monster. My mother.

I knew I would never escape her, she was everywhere, and two nights before my eighteenth birthday… She threatens everything.

Somehow she found out my secret. Somehow she found out about them. My monsters. My best friends. The only nightmares I could call my own. And when she threatens their very lives? I decided to run, leaving with a severed heart, realizing that they would wake on my eighteen birthday to realize that I was gone.

They would hate me for it… or so I thought.

But what happens when they hunt me down? What happens when they show up right when I truly need them? What happens when I realize that the men who chased me halfway across the globe… are actually my mates?

Mating Monsters is a standalone reverse harem novel that features possessive, territorial, and psychotic monsters that will do anything to keep their mate safe… even if it means hunting her halfway around the world. This book is filled with all the monster steam, terrifying creatures with a sweet streak for their girl, and an absolutely guaranteed HEA.

Warnings: This novel includes violence, parental physical and verbal abuse, PTSD flashbacks of mentioned abuse, swearing, and sexual content for +18.

213 pages, Kindle Edition

First published January 22, 2022

451 people are currently reading
1269 people want to read

About the author

M. Sinclair

107 books3,465 followers
M. Sinclair is a USA Today Best-Selling Author who can be found writing or thinking about her characters and plots nearly every moment of the day. With over 65 published works since her debut in 2019, her work spans from paranormal to contemporary romance rooted in extensive world-building and deep character development. M. Sinclair believes there is enough room for all types of heroines in this world, and that being saved is just as important as saving others.

Just remember to love cats... that's not negotiable.

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5 stars
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Displaying 1 - 30 of 346 reviews
Profile Image for Adrienne McFarlane.
473 reviews36 followers
May 13, 2022
This is a standalone book from the I.S.S. series world. You don't need to read the other books within the shared world in order to read Mating Monsters. From start to finish I was enthralled in the storyline and characters. The way Ms. Sinclair writes causes the reader to suspend disbelief. She makes you wish monsters were real.
Profile Image for Rebecca.
152 reviews29 followers
January 20, 2022
DNF @ 78%. The FMC is a weak ninny and cries at the drop of the hat. No personality. The MMCs pick her up into their arms all the time… often enough for the FMC to comment on it. Also, where’s the plot?
Profile Image for XxLaVampiresaAlexisxX.
1,158 reviews74 followers
January 27, 2022
After suffering the abuse from her mother, Isla couldn't wait to get out. When she finds three guys...er...monsters who are willing to do anything to keep her safe.


Mating Monsters is a quick paced standalone novella from the I.S.S world. I'm gonna give this a 🌟🌟🌟🌟💫. I must admit this is my introduction to the I.S.S world, so there was a bit of confusion on my end. However, after reading back a couple of times, I finally understood. I loooved Isla so much. She's endured so much yet she was strong-willed and was so innocent. There's something about big, scary monsters getting their cinnamon roll and protecting her at all cost. It's definitely my weakness. I definitely want to check out the original I.S.S series.
Profile Image for Miki’s⚠️ Safety Reviews & Rants⚠️.
736 reviews946 followers
August 26, 2023
4.5 stars ⭐️

🌟Brief Summary:

😈In a world we’re Nightmares and humans co-exist there is unrest between the two. It’s not also safe for Nightmares in the human world, enter ISS Is a safe haven for Nightmares but also a place to train their magic and help fight against threats to Nightmares.

”When the ‘fall of the veil’ occurred and humans learned that the nightmares that lived in the shadows of their minds, the dark figures they thought they saw while falling asleep at night, were real, everything changed.

🦋Isla had beaten and abused badly my her mother who is an employee at ISS.
Having tried to run away from her 5 times in the past she was put into a magical cuff to stop her from running and block her magic.

🕸️ENTER Team the Devourers…A Elite Nightmare team whose mission was to stop the evil humans were doing.
”We were called The Devourers because each of our magic held one singular element: we consumed others.
Ralos consumed blood.
Wyre consumed flesh.
Danos consumed memories”.


They find Isla badly beaten and take her in to care and protect her. Secrets are revealed and 🔥 mating is in the air.

Things I 💗 Liked/Loved
-‼️Fuck-in-Hell! I love MS men!! They are OTT JP obsessed like no other! They are loyal and hot as fuck… yes please🙋🏼‍♀️ I’ll take a harem of my own.

-This was a really unique and interesting new way to introduce monsters. I like the world and can’t wait to spend more time in it.

-it was a quick read but a lot happened and it was very well flushed out.

-In MS fashion 🫶🏻we get lots of feels and they are overall really enjoyable reads

Things I Did ☹️ Not Like
-I was confused about the mating, fucking and sleeping around rules of this world. It was clear her men were not V but with all the rules I was confused as to who they would have slept with.🤔. And is mating just fucking? It was highly contradictory. People could only mate with their own power class or they would die. And mating is taken seriously for breeding and Nightmares don’t fuck like humans. And female Nightmares are more rare than men….So explain to me how all this works. I hate reading new worlds esp ones with mate without CLEAR GUIDELINES.

-Isla was beaten down so I understood her mentality but COME ON GIRL. There is also just plain common sense. When she would find out things about her mom or her past or have to make serious decisions she was just plain stupid at times. Like her brain just didn’t register…. It got annoying by the end.

-😤All the sex or “mating” happened in one giant chunk at the end! Gah I hate this. Se should be spread out throughout the book so it doesn’t all just run into one long 10 chapter sex scene. It’s far more exciting and impactful when it’s weaved throughout the book.

🦹🏻‍♂️ Hero: RH
Dranos - 22yr -class A -Night Terror- pet name/Raven
Wyre- class A —Wendigo- pet name/beauty
Ralos- class A Dhampir- pet name/pet

🦸‍♀️ Heroine:
Isla- 18yr- thinks she is a class C but there is more than meets the eye when it comes to her magic and her history

💭 POV:
Multiple first person

🔥 Burn Rate:
Med slow

😡/😍 Angst level:
Medium

❤️‍🔥 Sexy times & Descriptive sex:
🔥🔥🔥🔥Absolutely! They were hot as hell but just to back to back for me

🌓 Push/Pull:
Minor- they think it will kill her to mate w her to everyone tries to keep their distance.

☠️ OW/OM Drama:

🤮 OW/OM Sex / Fluid or DNA Exchange: none

🤬 Cheating: nine

👰🏼‍♀️ Virgins:
Isla is a V
The harem Is not a V but their history unclear

⛈️Separation/ 3rd Act Breakup:
Yes For a few hours/ self sacrifice

Safety⚠️Triggers🗡️:
Child abuse
No condoms
No safety talks

🌈Epilogue:
Yes 3 mo and 3 years later

🥂HEA:
Yes

My opinion is just that… MY OPINION.
I know we all get passionate about our favorite reads and characters but we should respect each opinions a thoughts. ~Thank you
Profile Image for Annette.
3,847 reviews177 followers
January 17, 2022
I have no idea where all those monster books are all of a sudden coming from. I have no idea why all of a sudden everyone starts writing about dating monsters. I'm a little uncertain if it's my thing, but I'm pretty sure we're gonna discover that one monsterbook at a time. Since I loved the other book by this author, and mostly the writing style that really worked for me, I was quite happy to give this one a try, especially since I was offered an arc.

This book was incredibly heartwarming, cute and very satisfying. And that's mostly because Isla's situation is described in such a way that within a few sentences I was rooting for her. It's hard not to feel sorry for her, not to wish for her to find people to truly love her, not to root for her happy ending. And since Isla starts at the bottom, with loads of room to grow, she eventually has an amazing character arc only making me love her more.

Since this is a stand-alone novel in a universe that already has an entire series focussed on it, which I didn't read, I was a little afraid that maybe the world building would be confusing. However, Sinclair really explains how this world works and what the rules are without needing endless info-dumps to do so. I don't feel like I missed much information. I certainly didn't feel for a moment that I couldn't follow what was going on or why something was happening.

And as if an amazing main character and interesting world aren't enough already, Sinclair also adds an interesting plot and three very amazing guys. We're dealing with monsters here. We're dealing with a little danger and yet Sinclair manages to keep the balance between dangerous and caring, between threatening and protective and between being romantic and being possessive. They were exactly what Isla needed to feel save, loved and to grow into her amazing monstrous self.
Profile Image for Stephanie.
769 reviews1,084 followers
February 26, 2022
This book reminded me of the many, many fantasy books on KU with the premise of: hot, powerful, wounded girl is saved by the heroes. Seriously, I’ve read like seven different series with that plot.

This book condenses it to one book and twists it to be a little more paranormal/monster - the heroine is abused by her mother and the world is made up of “nightmare” type demons/beings.

Ultimately, the world building was lackluster for me as I found it hard to understand. There are different classes of nightmares but then we learn she’s part water sprite… We learn that some humans keep nightmares captive but - how? Why? So do magic beings live in open with humans?

And the romance was… awful. Two minutes after meeting her for the first time one of the guys thinks about getting her preggo - literally is like, “I wanted to see her round with our child.” No chemistry, and sexy scenes read very formulaic and stilted.
Profile Image for Diana R. Johnston.
Author 3 books55 followers
January 30, 2022
shocked

So this was one of those heck, why not books. Paranormal romance isn’t my thing and neither is reverse harem but this… well it might just change my mind. The story has me all in my feels and the spicy scenes were not the dominant part of the story. If you are looking for something to give these types of books a try I highly recommend this one!
Profile Image for Annelie.
684 reviews25 followers
April 19, 2022
Love this universe!

ISS is a very well built world and as I love monsters RH romance, this book totally fullfiled my expectations! It's a standalone story which takes place before "ISS, Soothing Nightmares", the story about Arabella and her nightmares.

Isla is a broken (but not so much) girl who lives in the ISS, a sanctuary for nightmares. Repeatedly abused by her mother, she just waits for her 18th birthday to flee and build a new life. After having been harshly beaten, she's rescued by three of the most terrifying (but also hot😏) nightmares of the sanctuary.

I like how dedicated the guys were and how they protect Isla from the moment they met her. Nightmares mate for life and it's a kind of instalove when they find their mate♥️ So no hesitant assh*le guy here, just hot possessive monsters.

I can't wait reading the last book of the serie about Arabella and hope that other standalones or serie would takes place in this interesting world.
Profile Image for Charlotte.
3,963 reviews63 followers
January 15, 2022
Mating Monsters is set in the I.S.S world and some of the characters from other books in this series pop up briefly in this standalone book. Which i liked

Isla has been through a lot of hurt and abuse at the hands of her mother. She was truly a nasty piece of work. It has left Isla distrustful and unsure of everyone. Only she isnt like that with The Devourers - Ralos, Wyre and Dranos. Three Class A monsters (highest ranking monsters) which everyone seems scared of but Isla. I loved how careful and considerate they all were with Isla. It was genuinely sweet and endearing. It was a great read. Dark in places but with likable characters. Loved It
Profile Image for Becca Sabala.
442 reviews31 followers
January 11, 2022
I loved everything about this!!!

From beginning to end I was sucked in.
I immediately loved the guys, and Isla clutched on my heart from everything she had endured. Even though she was clearly broken, she never let that stop her from accepting the devotion from her mates. This was all new for all of them, but they figured it out together and made the best of the circumstances.

There's nothing I love more than a woman who can bring the big scary men to their knees.
I really hope we get more of them in the future 😍
Profile Image for Libby Fowler .
605 reviews3 followers
January 13, 2022
Omg I absolutely loved this book, it was everything I needed and more! I love a good standalone and this was just great.
The whole story line was great.
Isla has had a horrible life, with her mother's abuse and lies she just wants to leave.
Then come Dranos, Ralos and Wyre, they rescue her and adore her. They protect her from her mom however she thinks that her mom will hurt them so she tries to protect them. I won't say much more as I don't want to spoil it. The ending was amazing and I love both both epilogues!
Profile Image for Esmeralda Silva Tenazinha.
1,048 reviews16 followers
January 15, 2022
I loved it! The beggining of the book is do heartbreaking, with Isla in the Rain, it almost seems that She Gave up and wants to dissapear. I loved it all, her nigthmares are the best all three of them and her Mother gets what She deveres the evil nigthmare she is. The artic scene is perfect, I never thougth the artic was so hot. A great book really. I want to read more I.S.S.
Profile Image for Cat H.
1,972 reviews219 followers
January 23, 2022
4 stars.
This was hot…but also the writing was a bit confusing at times.
The beginning was pretty slow and repetitive.
Then it got better when she met the guys, but it was also slow going.
All of it happened over a couple days, but it felt like it dragged until the last few chapters.

Those chapters were hot.
But the conflict that was going on was just background noise that they easily silenced.
It felt a bit anticlimactic.

I liked it.
The dirty talk was hot as hell.
But I feel like there should’ve been much more smut for how little the conflict really mattered in the end, and how long it got dragged out.
Profile Image for Poppy || Monster Lover.
1,813 reviews502 followers
March 9, 2023
3.5

I really liked the concept behind the nightmares and the classes of monsters based on power. I thought the relationship between humans and monsters was still a bit unclear by the end of the book though. The back story of the FMC was moving and her reactions to the MMCs appropriate. The author gave very little information about the MMCs’ backgrounds. There was also minimal information about the full extent of any MC’s powers.
Parts of the dialogue, both internal and external, were repetitive.
Overall, I think this could have been a fantastic book with a good editor.

Spice: 3ish scenes

Triggers: abvse, violence, horror themes, neglect, discussion of SA
Profile Image for Brooke.
1,589 reviews45 followers
March 19, 2022
Eh 2.8? A lot of the book was a 3 but the end was sloppy even if this is just a stand alone. Not bad, will read the author again and hope the series and longer books work better for me.
Profile Image for Book Life With Jen.
1,253 reviews21 followers
January 24, 2022
Having Nightmares never sounded so fun. ;)

M. Sinclair delivered yet another amazing story to add to your monster loving collection with Mating Monsters. This story was a quick fun read that took us on a quick journey into the world of I.S.S and a visit with all the nightmares that we know and love. If you’ve read any of the others books from this world then be prepared to see some familiar faces, along with some new.

Our FMC Isla is a quiet, meek and oh so innocent nightmare that has been abused by her mother for most of her life, never really knowing love or kindness, only wanting to escape the painful world she’s stuck in enduring torture and treatment beyond imagine. When suddenly, just days away from her eighteenth birthday, she finds herself in the care of three men named the Devourers: the scariest and most vicious of known Nightmaress.

Dranos, Wyre, and Ralos are known for being ruthless, hard core and domineering, yet they all find themselves instantly enthralled by Isla. I love how possessive they are and how willing they are to do anything for her—even to the extreme at times. And though Isla knows she should be intimated by their ranking, and that most likely they would never work, she finds herself feeling for them as well.

What ensues next is a mission to save Isla from her controlling mother which leads them on a journey of self discovery and secret revelations regarding Isla’s past. And while I did love the story, the characters and the overall plot i do wish that we had more time with Isla and her men because I just feel like their dynamics screamed more than what we got. Mainly more steam 😂 Though don’t get me wrong! Their chemistry, connection and possessiveness was fantastic! I just wish we had a rad but more of their domineering interaction.

Overall if you love possessive, protective, alpha males that will do anything for their fated mate then this one is for you! This story was beautifully written, the characters were diverse and easy to connect with and I truly love this wonderful world—I just want more!!!
Profile Image for Chelsie Lucas.
1,077 reviews23 followers
March 28, 2022
I really like this. I liked the nightmares I liked the world building I liked the fact that it was a standalone but you can read the series if you want however it’s not needed. I like the guys and the meeting I wish we had more as far as the magic went also as far as her getting any retribution herself. The guys are the ones that handled all of it and she’s supposed to be super powerful but the author never give gave her a chance to explore that or to demand justice herself and I’m a sucker for the FMC getting to do that.
It didn’t take it away in my book from the story it just kept it from ever having that five star feeling. Definitely a fun easy read and I will probably reread it in the future.
Profile Image for Cheryl Sedman.
1,159 reviews11 followers
January 19, 2022
I really got stuck into this book. The main character Isla you just want everything to go right for her, especially after everything she has been through with her mother.

When she is found by Ralos who takes her home where she also meets Wyre and Dranos. From here we see the story picks up and go through the twists and turns. Which also give you more light into Isla and her past. With some steamy scenes this book ends on such a high. Especially with the two epilogues where you get to see them in the future. Totally freaking awesome
Profile Image for Jennifer.
450 reviews26 followers
January 11, 2022
Isla has a chance meeting with three Class A monsters after another another beating by her abusive mother. Isla believes she is a Class C and unfortunately it’s dangerous for the two classes to mix. When Dranos, Wyre and Ralos decide to keep Isla no matter her classification, her Mother gets involved to once again to try and hurt her. Will Isla ever get her happy ending?
Profile Image for Well Read Nurse.
593 reviews238 followers
January 18, 2022
Nightmares Mates and Demons oh my

I love this world! Good lord its amazing! The power system the classes! The possessive men! I am so inlove with this!!! Infant rave enough!


Took a minute to get to the spic only because of the fear of potentially killing her! But gah the "do you need to come little raven?" I FLIPPING DIE
Profile Image for Rayne [semi-hiatus].
104 reviews6 followers
January 22, 2022
4 stars. Sizzle sizzle sizzle, the chemistry are over the top. If you like OTT possessive alphas mixed with monster elements, this book would be perfect for you.

The last 20% felt a bit rush and some scenes make me raised my eyebrow. But I do enjoyed the first 80% and can’t wait to get more monsters alpha story from this author!
Profile Image for Angela Denny.
1,055 reviews6 followers
January 15, 2022
This was a great book. You go through all the emotions as you read it. Isla grew up believing she was nothing. Her mother was a monster who abused her. One night she meets three nightmares and her life is changed forever.
Profile Image for Debbie Eyre.
5,904 reviews116 followers
January 17, 2022
This is a great stand alone read set is in I.s.s universe. Our female mc is Isla and she is incredible despite the awful and horrible life. Her mates are fantastic and idolise Isla even though they don’t know her or her story. It’s a well written, dark and exciting read full of pain and anguish and is the stuff of nightmares and so worth a read!
Profile Image for Alaysia.
662 reviews10 followers
February 2, 2022
ISS Stand-alone!!!

Fantastic stand alone in this creative and amazing world of Monsters! Seriously amazing writing and love all these characters. Must read!
Profile Image for Punkin.
983 reviews
June 3, 2022
Well

Went way faster than the soothing monsters series but I remember them mentioned in it. So I'm glad I found this one.
Profile Image for Meg.
523 reviews1 follower
February 14, 2022
loved it but it was a bit short for my tastes, I wanted to see a little more tension and slower burn.
Profile Image for Rebecca.
4,054 reviews
January 17, 2022
Her mother should’ve been put down along time ago along with her demented security guards. I cat believe everything her mom put her through. Thankfully her nightmares found her
This entire review has been hidden because of spoilers.
Profile Image for a seductive cactus.
294 reviews292 followers
April 7, 2022
1 “the cover is cooler than the contents” star
Trope: idk, monster romance with a Mary Sue FMC?

An interesting premise but poorly executed with too much telling rather than showing. Characters never got fully fleshed out and just felt like empty archetypes, especially the FMC. Excessive dialogue from the villain explaining why they are bad and what bad thing will happen… but then it never happens because everything is magicked away and wrapped up in a neat bow.
This entire review has been hidden because of spoilers.
Profile Image for Rachel.
2,345 reviews132 followers
January 15, 2022
M. Sinclair is one of those authors that I've always wanted to try but for some reason didn't. That is until the Monarchs of Hell series, her co-write with R.L. Caulder and I loved it so much that I just knew I had to read her newest release right away and Mating Monsters did not disappoint, I loved the story so much. The world was interesting, characters I couldn't help but feel for, a bunch of past drama, an uncertain future, and three hot monsters up the steam factor considerably. Yes, please.

Monsters are people too and they have problems just like humans. Isla is the leading lady in this story, she's kind and so innocent, but she has been abused by her mother for most of her life. She has been broken down so much and while she doesn't have much hope she has a little. Isla didn't let her mistreatment turn her into a bitter and angry person, Isla is a kind soul who only wants to help children. While she may have been almost completely beaten down she didn't give up hope in changing her circumstances, she had a plan to escape, she's willingly going after her freedom.

Then enter Wyre, Ralos, and Dranos, the monster team known as the Devourers. These are some powerful monsters and they intimidate almost everyone they come into contact with. However, Isla doesn't have the typical reaction, she isn't really scared of them beyond what she has been conditioned to. And they are different with her, kinder, softer, a lot more caring. I loved reading from their perspectives because it gave me a better understanding of how strong their feelings are. I mean this is a standalone so it's a pretty fast-paced story and reading from their perspectives helps fill in gaps. The guys are a little gruff but I love them, I especially love them with Isla, they so easily opened up their hearts to her and are extremely possessive of her, I loved it.

This world is fantastic! It's so unique. Supernaturals are called nightmares, there are different levels of power, different classifications of species, all sorts of unique supes are mentioned. There are dominance fights, mating rules, secret communities, and the I.S.S. The I.S.S. (Insitutum Sequuntur Somnia) is an organization that takes on the responsibility of rescuing, rehabilitating, and housing nightmares. In this world, the nightmares may be powerful but it's humans that are a danger to them, they live grouped together hidden in communities and need all the help they can get. Sinclair has created a very clear picture of their past, what problems they face, how they are treated, and what kind of world awaits them. She managed to pack all of that in a standalone that seem to fly by. I finished this book so fast and loved every single second of it, especially the ending.


I want more of this world and I plan on getting it. Mating Monsters was fabulous and there is another series set in this world, heck some of the characters from the original I.S.S. universe even made an appearance in this one. I can't wait to dive back into this world.

Profile Image for Seraphia Bunny.
2,111 reviews34 followers
January 23, 2022
Mating Monsters is a reverse harem standalone paranormal romance novel that tells the story of a young woman simply wanting to escape to a place free from the one who has made her life a living nightmare. But the dynamics change when she crosses paths with three nightmares who are intent on keeping her for themselves.
Being a huge fan of paranormal reverse harem novels I was excited to pick this book up only to be disappointed. The blurb and the actual story...they just don’t match up. The author makes the mother sound like she sees all, knows all, and is truly powerful. She’s not. This book was far from what I was expecting based on reading the blurb which is what caught my attention and piqued my interest. This book has a lot of potential, but it falls tragically short. The storyline is robbed of certain elements by the mother giving a “villain” speech, and the story never develops in that vein. Why take that away instead of pushing forward in that direction and really bringing in the drama this book so desperately needed?
For me, things go too much in the main characters’ favor. This causes the story to just be too heavy in conveniences that work for them. There are a couple of exceptions to move the storyline a bit, but not enough. While the story matches the title, it’s not enough. If you want steamy, you definitely get that, but there is no true romance development (there can’t be in a span of a few days).
I kept waiting for some moment of redemption for this book, but it just never really comes. The drama is minimal where it matters most, and played up in areas where it honestly goes nowhere. I’m rating this book a disappointing 3.5 out of 5 stars. If this book had axed the “villain” speech, added in the drama hinted at, and the romance developed this book could have been really good. Granted it probably wouldn’t have been a stand-alone novel, but that might have been for the best. If you enjoy steamy stories then you’ll like this story. If you want more, you’re going to be disappointed.
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