Tempted by the Alien Mercenary

Monster Mercenary Mates #7

by Robin O'Connor

He was built to feed on fear, but I’m the only one who ever tempted him to feel.

Frederique

I woke in a shattered stasis pod, centuries too late, on a world drowning in water and secrets. My mission? Gone. My crew? Dust. And the only being who’s kept me alive since then is an alien mercenary wrapped in living silver and danger. He’s not just terrifying, he’s mesmerizing.

I should keep my distance. I know better. But every time his dark gaze settles on me, every time that shifting symbiont flows over his skin like armor and art, I forget who I was supposed to be. His power should terrify me, but it tempts me. He tempts me.

Even when I discover the truth about my mission. Even when enemies rise and survival hangs by a thread... I still look at him and wonder what would happen if I let myself fall.

The Sineater

She calls me mercenary. Monster.
But she doesn’t run.

I was sent to kill, not to feel. My symbiont craves agony like air, but her emotions, bright and tangled, taste like hope. I want her. Not just her body, but the calm in her thoughts, the fire in her fight. I want to protect that light, even as I know I’ll destroy it.

But I am always hungry. Always feared.
And if I take what I want, I may never let her go…
Even if loving her is the one thing that could break me.

This is a standalone novel and the seventh book in the Monster Mercenary Mates series. This sci-fi monster romance features a darkly sinful ancient warrior, a plucky, bossy FMC, a mysterious animal sidekick, and a steamy HEA.

Genres: Romance, Science Fiction Romance, Science Fiction

276 pages, Kindle Edition

Published December 9, 2025

About the author

Robin O’Connor is an author who loves to write about strong, alien heroes and quirky heroines. She lives with her husband and son along with a couple hundred books (hers, definitely hers) and probably just as many computer parts (her husband’s). Her house therefore probably resembles something like a mad-scientist’s lab on any given day.

She’s always working on at least a half dozen projects at the same time but is never without time to answer questions, write up funny extras or hang out in her group online to speak with her readers.

Join her mailing list ➜ https://robinoconnor.ink/

Join her on Facebook ➜ https://www.facebook.com/RobinOConnor...

Visit her website ➜ https://robinoconnor.ink/

Follow her on Instagram➜ instagram.com/robinoconnorofficial/

Reviews

[Sandra Sanches · Rating 5 out of 5]

"I rather like the way you moan Sin when you come on my tongue.” Sineater

Finally,the most dark and misterious mercenary of the Varakartoom falls,and falls hard!
The connection between Sineater and his simbiont is fraying,the crew is happy and there's no heavy feelings to feed Val and him.
So he goes to a ,possible,last mission into a dangerous waterworld and finds the unexpected, a human female in crio.
Frederique wakes to the shocking knowledge, that she was 700 years in crio.
Not going to resume because it's too good to spoil the fun.
One more incredibly good addiction to this series, Robin O'Connor has the gift to outdone herself with each new book and blow my mind everytime.
Sin and Freddy interactions, the banter,the clash of wills and chemistry are absolutely delicious.
Add to that, dangerous situations, a villain following her ,Sin struggling with his feelings, Val weakening,one of the Mercenaries fighting for his life and all antics from the crew and mates.
Absolutely unputdownable!

[Lynn_G · Rating 5 out of 5]

Every time I read another Robin O’Connor book I am so pleased to find that each one is better than the previous book, and this sci-fi romance is no exception.

Focusing on human Frederique, and the Varakartoom’s resident indestructible and irascible grump Sin, the author spins a gripping and steamy tale of heartbreak, loss, and redemption. Both Frédérique and Sin have Been Through It (no spoilers here!) and their epic adventure is a harrowing and gratifying read.

I received an advance reader copy from the author and booksprout, and I’m sharing my honest review.

[Anna Svoboda · Rating 5 out of 5]

I have to admit, I never liked Sin (who did?) but this book fixed it! It's very different from the others because Sin is still quite the alphahole but his reasons are explained well enough so that you'll actually start liking him. I loved how Frederique didn't just roll over for him and how she firmly set her boundaries - you don't see that often in books. I'm always happy so see the characters from previous books play more important parts in the current book and this story definitely fits. It keeps you at the edge of your seat until the last page!

[Bridget Thomas · Rating 5 out of 5]

Oohhh this book was very intriguing! Sin is a very interesting character and this story was fun and sexy. I was lucky to receive a free digital copy to read and I really enjoyed this read! I always rate a book higher when it makes me cry, and this book was a winner there. I felt all the feelings with this one and will definitely recommend reading this book over and over!!

[Chandra Luna · Rating 5 out of 5]

Some romances make your heart race.
This one makes it thunder.

Tempted by the Alien Mercenary by Robin O’Connor is the kind of sci-fi romance that grabs you by the emotions, shakes you through action and intimacy, and then whispers, “You’re not leaving until the end.”

And trust me—you won’t want to.

🌊 A World Lost. A Woman Reborn. A Monster Who Learns to Feel.

Frederique wakes centuries too late in a shattered stasis pod, stranded on a drowned world and stripped of everything she once knew—her mission, her crew, even her purpose. What she still has is grit… and the unshakeable instinct to survive.

Enter him: the Sineater.

A lethal mercenary wrapped in living silver, a being designed to devour fear and weaponize agony. A monster to everyone else—yet somehow, impossibly, not to her.

From the first moment he looks at her, something electric sparks, something undeniable and dangerous… something fated.

❤️‍🔥 A Romance That’s As Emotional As It Is Explosive

This is a fated-mates story with heat that feels earned and intimacy that feels inevitable.
Their connection doesn’t just simmer—it consumes.

Frederique should run. She knows it.

He should push her away. He tries.

But her emotions taste like hope to him. Her courage awakens something he was never meant to have. And her quiet strength becomes the one thing he can’t fight.

It’s tender.
It’s scorching.
It’s beautifully, achingly inevitable.

💫 What Makes This Story Shine

✨ Dual POV that feels deeply personal
We get Frederique’s resilience, humor, and scientific wonder—and Sin’s raw, conflicted hunger for connection he believes he doesn’t deserve.

✨ A symbiont with a mind—and agenda—of its own
Its refusal to leave Frederique behind is both hilarious and strangely heart-squeezing. It’s not just alien biology—it’s character, devotion, and destiny.

✨ A world that feels both eerie and enchanting
O’Connor builds an ocean-drenched planet full of secrets, danger, unexpected humor, and a crew whose antics add perfect warmth to the suspense.

✨ A love story built on acceptance
Frederique sees past Sin’s armor—literal and emotional.
Sin learns, slowly and painfully, that he’s allowed to want, to care, to choose.

✨ An ending that feels earned, heartfelt, and beautifully hopeful
The symbiont arc. The danger. The emotional payoff.
It all lands exactly where your heart wants it to.


This book is for every reader who wants:

💙 Fated mates with depth
🔥 Action and spice intertwined
🖤 A “monster” hero who becomes undone by one woman’s light
🌊 A world so vivid you can taste the salt on the air
💫 A romance as powerful as it is tender

Tempted by the Alien Mercenary is thrilling, emotional, lushly written, and deeply addictive. It’s not just a story about surviving a harsh alien world—it’s about finding the one soul who makes that world worth surviving at all.

If you love sci-fi romance with heart, heat, humor, and characters who stay with you long after the last page… this one is a must-read.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Abbey · Rating 5 out of 5]

Well, Sinny, you were the absolute last person anyone on the Varakartoom expected to go out on a mission and return fully bonded to a mate. And while it was a shock, it's clear that Captain Asmoded been secretly hoping you'd get this kind of happiness and peace too.

7 books into this series and The Sineater's back story has been the most anticipated as there didn't seem to be any past or connection to him and the crime lord Julima, like the rest of the crew seeking revenge. And we find out that after the Captain befriended him and gave him sanctuary aboard the vessel, his new and only friend's vendetta became his purpose. Plus, Sin and his symbiant Val needed negative emotions to survive and a ship full of angry, vengeful, damaged men would surely give them a steady diet of darkness. What was very interesting to discover in the second half of the book was that the bonding between Sin and Val was actually incomplete and they were meant to be able to siphon and feed off all spectrums of emotions and that there had been a glitch during the process to cause this, instead of the prevailing belief of Sin's people that he was at fault and viewed as less than.

Now, Frederique has taken over as the female coming into their lives with the worst trauma. She and her small crew left Earth on a diplomatic mission to find other aliens to help their planet with potential colonizers and they go into a two year stasis to help them travel the distance needed between quadrants. Next thing poor Frederique knows is that she is awakened 700 years in the future, stuck in her very sabotaged ship and the rest of her crew murdered in their stasis pods. On top of those major shocks, the only other living things is a scary looking alien covered in body armour and swirling silver, with a silver animal of sorts for his companion. If Frederique hadn't extensively studied alpha quadrant alien species for her college education and her mission, she might have been as easily dissuaded from any positive thoughts about Sin and Val, but that knowledge made her more fearless about approaching him than anyone he's ever met.

Tossing the mate bond in the mix, her tenacity, his stubbornness, the close confines of her immobile ship, as well as some sea creature on board hunting them, and we have all the elements of a sexy, snarky and volatile mating claim. Because of her basic understanding of his species, even Frederique handled the reality of the mate bond better than Sin, and he was in such denial, even with all the signs. So watching this usually stoic and composed man navigate these foreign positive feelings and the obsession and jealousy of the fresh bond was a treat. And ending up aboard the Varakartoom with its group of alien males and their human females with similar experiences gave Frederique the best possible opportunity to integrate into this new life.

[kymagirl · Rating 5 out of 5]

He was built to feed on fear. She makes him feel everything.

Frederique wakes in a broken stasis pod seven hundred years too late, her mission erased and her crew long gone. Trapped on a planet covered in ocean and secrets, she isn’t alone. A Talacan mercenary wrapped in living silver is the only reason she’s still alive. He’s not just dangerous. He watches her like she already belongs to him.

Sin was never meant to feel. Designed to kill, survive, and carry Val, a symbiont that feeds on pain, he’s spent years locked in darkness. Then Frederique crashes into his world. Her emotions are sharp, bright, impossible to resist. She should terrify him. Instead, she tempts him.

What starts as survival shifts into something deeper. As secrets surface and danger closes in, their connection tightens. But Sin’s instincts clash with everything Frederique is starting to mean to him. And when trust is the only thing holding them together, it might also be what saves them.

Sin begins as closed-off and emotionally starved, while Frederique is disoriented but determined to adapt. Val, caught in the middle, shifts from a predator to a protector as their bond evolves. Through slow trust, sharp honesty, and quiet courage, they go from tense allies to something unbreakable. This isn’t just a love story. It’s three beings learning how to choose each other, fully and freely.

A steamy, slow burn, fated mates, forced proximity, alien mercenary romance built on emotional hunger, found family, and the aching pull of connection. It explores identity, trust, trauma, healing, belonging, and the transformation that comes from being seen and chosen. At its core, it’s about an alien who’s only known darkness, a woman who brings the light, and the bond that forces them to face everything they’ve buried.

The Elevator Pitch: A deadly alien mercenary bound to a living symbiont meets a human woman seven centuries out of time, and nothing about the universe feels the same. Their connection sparks with danger, slow-burning tension, and a bond neither of them understands but can't ignore. Steamy, emotional, and charged with fate, it’s a romance built on survival, trust, and a love that rewrites everything.

[DebbieReadsBooks · Rating 4 out of 5]

Independent reviewer for BookSirens, I was gifted my copy of this book.

This is book 7 in the Monster Mercenary Mates series, and I do RECOMMEND you read the other books before this one. Not strictly necessary, but it will give you a better view of Sin and how the crew views him and his symbiont, and also how far the crew of the Varakartoom have grown since we firct met them (not just in people size either!)

Sin is Talac and feeds off negative emotions. Freddie left Earth some 700 years ago and is discovered by Sin when he goes on a mission. But something else is hunting Freddie, and there appears to be something wrong with his symbiont, who attached itself to Freddie! Never happened before.

What I especially loved about this one, was that I've been watching Sin, through 6 other books and he really does not disappoint!

Sin is dark and deadly and he comes with rumours of being immortal. The rest of the crew steer clear, mostly, but Sin and his symbiont need to feed on the negative emotions. For the most part, he can get enough but the crew is getting loved up and the emotions are different. Not filling him or Val up enough. Meeting Freddie does something else, something profound, and I loved that he really knew, once Val attached herself to Freddie, who she was to him. He denies it, it spectactular fashion! But he does come good, though.

Freddie, 700 years out of her time, takes to being Sin's mate like a duck to water, she really does. She fits in well with the other women now on the ship.

I would have liked more about what happened for Freddie's ship to be in the water on that planet, something more explained. And then again, when Sin fully bonds with Val?? What does that really mean?? I needed more about that, I really did.

Still, a long awaited addition to this series, and the addition of a couple new characters, the Son of Ragnar, especially. I feel he might pop up again!

4 very good stars

*same worded review will appear elsewhere

[Kelly · Rating 5 out of 5]

Oh So Tempting!

Tempted by the Alien Mercenary is book 7 in the Monster Mercenary Mates series and it has it all! A feisty and brave heroine, a mysterious and dangerous hero and his enigmatic sidekick, a creepy and sinister foe, plenty of supportive formed/found friends and family and so much spicy attraction to melt your heart!

This is the ultimate grumpy/sunshine with a menacing hero turns cinnamon roll, a touch of vulnerability, treacherous action and tons of adventure. This is one of my favorite books yet!

You could read this as a standalone book, it does have its own HEA, but I absolutely recommend reading this series in order. You will become as hooked as I am with the engaging characters, original storylines and overall series arcs that have kept me coming back for more!

If you want to dive deeper into the creative world building Robin O’Connor has created I also suggest some of her other series’ and novellas that all tie into this same world. Although you certainly could read any of these series’ in any order, this would be my reading order recommendation for maximum enjoyment!

1. Prequel novella, Gladiator’s Sanctuary, I got this via Robin’s website.
2. The Gladiators of the Vagabond series; read in order. (Be sure to read Enticed by the Alien Chef after Broken Logic to see how those main characters got their start.)
3. Two holiday themed novellas; There’s An Alien Down My Chimney and There’s An Elf In My Cockpit.
4. Taken by the Gargoyle King; a novella related to the Gladiators series.
5. The Naga Hunter’s Lost Mate; prequel to the Serpents of Serant series, I got this on Robin’s website too. 6. The Serpents of Serant series; read in order.
7. Protected by the Alien Mercenary; is part of the My Monster, My Protector series but feels like an introduction to Robin’s Monster Mercenary Mates series.
8. The Monster Mercenary Mates series; read in order!

[April Nicole · Rating 5 out of 5]

This is the seventh book in the series and hopefully not the last. That doctor and the tentacles Robin we deserve that.

I have read 6 out of 7 and it was a relief to read sins story. He is the darkest grumpiest meanest. Than you got the FMC literally with nothing. No home no money nothing eetc.He tries to fight it at first and there's a bit of a rollercoaster ride. FMC was really strong and handled the ride well. She didn't hold grudges and was willing to work on their relationship. The spice was middle of the board. It was there just nothing to wild. Not bad but not the spiciest I've read. The lack of details is made up with the abundance of it. He didn't even make it back to his ship after rescuing her to seal the deal.

As this is a series I find it prudent to mention Brace's book. I didn't even crack open to test it out but I didn't feel as if it was fair to Robin to leave this feedback on a book I haven't even read.
I didn't read one of the books because I felt as if it was irrelevant to the story. At least at that point in time. I had considered going back to reread after I finished this book. However there's very little to no mention in the last two books about Brace. Just vague references. I felt that would have been a good place for the Drs story possibly. There wasn't enough development with brace in the main plot. This book shows further evidence of that. Still an engaging series.

lastly I received this as an arc and am under no obligation to leave this review. I also wasn't under any obligation to read the previous books in the series as well.

[Cathy Geha · Rating 5 out of 5]

Tempted by the Alien Mercenary by Robin O’Connor
Monster Mercenary Mates #7

~ Excellent addition to the series and one of my favorite book by this author so far ~

What I liked:
* Frederique “Freddie” Moretti: human, sent with a team into space, wakes 700 years later from her stasis pod, meets an alien and his symbiont that will change her life.
* Sineater “Sin” + another name that shows up later: ancient, alien, dark glitch in the symbiont ceremony with Val, unique to his species strong, lethal, protective
* Val: symbiont bonded with Sineater, feeds on negative emotions, fluid and able to change shapes, strong, protective, intriguing
* The instant fated mate vibe between Frederique and Sin and Val feeling it, too
* Thinking about whether humans will age the same in outer space as on earth and how that might impact Sin and Frederique in the future
* The arrival of Devan’Car and the excellent skills he brought to help more than one character
* Getting to catch up with other characters from previous books in the series
* The plot, pacing, settings, and writing
* Escaping into a fantasy world for awhile

What I didn’t like:
* The UAR – the more I hear about them the more I hope that at some point in the series some of them will be brought down
* Having to say goodbye to this fun fantasy world till the next book is ready to read

Did I like this book? Yes
Would I read more by this author? Yes

Thank you to the author for the ARC – This is my honest review.

4-5 Stars

[Keyyyy · Rating 4 out of 5]

Sorry in advance if this is all over the place.

Nice to finally learn more about Sin, I still think he's a piece of work but he was sweeter at the end, now that he's finally at peace with himself. I would have liked more about his backstory, how he became a son of Ragnar, what/who are they exactly ? Maybe it will be explained in another book or series in the same universe.

only my opinion, I couldn't see how I would enjoy a story about him, as I don't find him attractive and once again, even if he's feeding off negative emotions, he's :/. I always liked his rationality (and sass) but that was his only quality to me ... but I like men losing their minds because they love their women so much more than his defaults, so in the end, I kinda enjoyed this. He grew on me a bit.

Freddie is stronger than me, because even with a mate bond, my pride would have won and I'd left him. But she lost everything and everyone she knew and love, I'm happy she gets to have a fresh start aboard the ship. I didn't understand how and why her crewmate betrayed them, sabotaged their ship and mutate into black alien goo.

I finally caught up to all the series, saved Asmoded for last weirdly enough (and I loved it), can't wait to see more of those mercenaries !.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Lifeofkel · Rating 3 out of 5]

I’d been excited about this book ever since it was announced. I was eager to see how the author would handle redeeming a character as unapologetically flawed as Sin. Unfortunately, I’m not sure the story fully achieved that for me. While the crew’s celebration of his healed bond with Val was heartwarming, I didn’t quite feel that Sin had earned such presumed devotion?

The dynamic between the two main characters also didn’t really click for me, possibly because their chemistry never fully came through on the page. Sin’s brooding nature contrasted interestingly with Frederique’s resilience as the lone survivor of a sabotaged mission, but I struggled to understand what drew her to him, especially early on, when he hadn’t yet shown much that felt worthy of her affection.

The introduction of the new character from Sin’s past also felt somewhat abrupt, though it does seem to lay intriguing groundwork for the next series installment.

Overall, this one didn’t land quite as strongly as I’d hoped from an author I usually automatically read. I couldn’t shake the sense that writing Sin’s story might have been especially challenging, which may explain why the book felt a bit disjointed in places.

[Avis · Rating 5 out of 5]

Welcome back to the Varakartoom, where strays are " collected". This is making the Sineater 's task of feeding his symbiotic Val very difficult - to the point of starving. There is no or very little negative emotions to feed on any more, with the crew finding their mates. . He goes on a mission to alleviate it. And what he finds is more than what he bargained for.

I loved Frederique (Freddie to her friends). Courageous, smart ( after all she is a scientist, with a scientists curiosity). And according to Sin delicious with her terror.

I loved the chemistry between them. How she eventually realizes she is not afraid of him. And has a back bone.

We learn Sin's real name. And he gets help from a n unexpected source with Val. His two ladies are his world. He is obsessively protective of both .

Loved the twists, and go figure -Sin does have a sense of humor and can laugh. Not that he does it often. But more since he met Freddie.

Loved Val and her knowing who Freddie is to Sin before he can even comprehend .

Acton through out, challenges on more than one front, steam to the eventual romance. The HEA was spectacular.

I received a free copy of this book via Booksiren and am voluntarily leaving my review .

[Samantha Suitter · Rating 3 out of 5]

Not my favorite...

This one is my least favorite so far. From the very start of the book, Sin was an asshole to her. I stuck it out in hopes that there would be some heavy groveling and some serious changes, and while Sin did go through character development, I still don't think he treated her with respect. I understand that Fredrique was strong in challenging him all the time, but I feel like she should have stood up for herself more. Every time he was an asshole to her or he gave her the cold shoulder, she just forgave him immediately with minimal apology. She obviously seems fine with their relationship, and towards the end of the book, I hoped he has changed enough to treat her with love and respect, but honestly, I'm not convinced. This one really tugged at my heart strings because I feel like she deserved better than how he treated her, and their love story just made me feel sad. I do appreciate the author branching out and showing just because you have a mate bond, that doesn't mean everything is immediately perfect and happily ever after, but instead you have to work at it and properly communicate. Their relationship dynamic was not something I could relate to and made me feel a bit icky, which is very different from this author's other books.

[JLH · Rating 5 out of 5]

Sin has met his match. Him and his symbiance went to a inhabitable planet and found a spaceship from Earth crust under the 90% uninhabitable water planet. She has been in stasis for 700 years give or take a day. But for some reason the two of them hit it off once she woke up and the screaming stopped. This is a full of action and jealous who will protect his human to the best of his ability with his symbiot. Adjusting to being sleep for over 700 years and fighting your possible forever one takes a lot out of you. But there is a villain who is trying to keep her for himself. Thank goodness the symbiot knows better then send her bonding protective being. It's a good thing a lot of explanations are in the story in case you didn't know what is Symbian is and or some of the history that goes behind the alien versus human. Definitely action-packed definitely some nail biting scenes of other alien beings attempting to do no good. Love the story. Love the body and the unexpected relatable situations that occurred. Good read.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Shana W · Rating 5 out of 5]

I've been looking forward to this book. We finally get a peek into the head of the mysterious Sineater, who has always seemed so scary and sinister. We also learn more about his symbiont, Val, his terrifying shadow. They live off dark energy in others, but most people on the Varakartoom are just so happy now with their new mates that negative feelings have dwindled. To make matters worse, there is something wrong with the bond between the Sineater and his symbiont.

Sin chooses to take on a dangerous solo mission. When he gets to that water world, he finds Frederique, who has been in stasis for 700 years. She had originally set off on a mission to stop the UAR and their takeover of Earth, but she wakes to find that the mission has been sabotaged. There is instant attraction between these two MCs and it's fun to watch it play out.

I love the glimpse we get into couples from previous books who live on the mercenary ship, the Varakartoom. I also enjoyed the twists in the plot and the world building. I look forward to reading the next book in the series, as always.
I received an advance review copy for free, and I am leaving this review voluntarily.

[FRANCES COOPER · Rating 5 out of 5]

Sin went on a mission to collect negative energy that both he and his symbiot desperately need. What he finds instead is hope in the form of a brave little human scientist. Her mission was cut short when her ship crashed leaving her in stasis for 700 years. Frederique comes face to face with Sin after waking and even though she is intimidated she feels drawn to him and quickly learns that for her at least...there is nothing to fear. As a matter of a fact there is soo much about him to admire and maybe even crave. Strong character development makes you feel at home in a flash. Sin and Freddie must escape her underwater tomb while evading a monster that wants Frederique all for himself. Sin still has his original mission to complete. Keeping Freddie safe and doing his duty has Sin balancing every action with the need to keep his new love alive and well. We get to learn more about Sin which is great! I have always loved his dark brooding demeanor that occasionally showed us more lurking beneath the surface. Freddie is going to coax it out. Action! Adventure and true mate bonding! A truly addictive series! Love it Love it Love it!

[Tima · Rating 5 out of 5]

This story is dual POV, well written, and a fast-paced, action-filled, emotional and steamy, fated mates, sci fi romance between “Sineater”, the male alien mercenary lead, and Frederique, the female human xenobiologist lead. I chuckled at Sin’s attempt to leave without Frederique when he found her and his symbiont’s absolute refusal. I enjoyed Frederique’s determination to actively engage with the strange world she found herself in. I enjoyed Sin’s growing acceptance of their fated mate bond and his emotional development. I enjoyed the steamy intimacy between them. I laughed at the antics of some of the members of Sin’s crew. I enjoyed the somewhat creepy non-romance plot surrounding Frederique, and enjoyed the resolution of that. I enjoyed the resolution of the concerns around Sin’s symbiont which contributed to the genuinely happy ending. I enjoyed the set up for the next story which is for a character I’ve been waiting a long time to see!

I received a complimentary copy from the author and this is my voluntary honest review.

[Zelda · Rating 5 out of 5]

I have read several of Robin O'Connor books and have enjoyed every single one. So coming into this book I was excited to jump in. And jump in I did. I could not put it down. Dual POVs.... So well written. A page turner that keeps you wanting to know what's coming next. Action filled from start to finish. Fast paced that keeps you on the edge of your seat. Emotional and steamy at the right moments. 😍🥵😍

The Sineater, an alien who feeds on the dark emotions of othes but lives on a ship of happy couples. Frederique, the lone survivor of her crew who had been in stasis for over 700 yrs is rescued by Sin. Only for him to find his fated mate and then be in denial about it. Absolutely love that she calls him on his sh!t! 🤭🤭 Definitely love the HEA and closer that Sin was able to find! Swoon...🥰🥰

Even though this can be read as a standalone, I am looking forward to catching up on all the crew members of the Varakartoom.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Florencia · Rating 5 out of 5]

“Tempted by the Alien Mercenary” is the seventh book in Robin O'Connor's Monster Mercenary Mates series. The story follows Sin, an alien mercenary known as the “Sineater,” who encounters Frederique, a human who has been in stasis for over 700 years following the sabotage of her ship, the Lancing Light. Frederique awakens to a world completely different from the one she knew, facing the loss of her mission and her friends as she tries to adapt to her new reality.
It is an exciting and emotional story that explores themes of love, redemption, and the struggle to find a place in a hostile universe.
The author also introduces elements of intrigue and mystery, such as the arrival of another Son of Ragnar, Devan'Car, who offers a solution to repair the bond between Sin and Val.

I've always liked stories with pets, and this one is no different, since much of the book is about Val and Sin.

As always, Robin does not disappoint.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Lyndsay L · Rating 5 out of 5]

This is such a dynamic story. I loved every single moment of this book!! Robin has done it again. I was hooked from the very beginning. The writing is stellar, and on point. The action is non-stop and keeps you on the edge of your seat. The bad guys were beings I've never read before and kept me turning page over page to see where the story took us. I loved how Frederique and Sin got together. The chemistry between them, and the way Val integrated with Freddy. Reading how they came together made for a fun read, and the way that Freddy loves Sin even with how closed off he can be. The writing on books keeps you smiling and laughing at the humour of this rag tag group of friends that came together to be a formidable force, and the way they each find the women that are made just for them and make them even better. These women are strong in their own ways and match their mate so well. This is a must read!!! If you haven't read any of this series don't hesitate to start it now. You won't be disappointed. I cannot wait to see what else Robin has in store for us.

[Jen Reading · Rating 5 out of 5]

Sin (The Sineater) and his symbiont, Val, literally feed on dark emotions. Val hasn't been finding enough to feed on while aboard their ship, Sin's friends have found happiness with their mates, leaving Val hungry. When Sin volunteers for a mission—both to get a break from all the happy crew members and to feed off the fear of those he will assassinate—he discovers Frederique, a brave human xenobiologist rescued from over 700 years of stasis.

In the face of finding his mate, Sin is more than the regular run-of-the-mill grumpy MMC; he tries to deny the mate bond, cruelly pushing her away. Frederique is brilliant, calling Sin out on his denial and cowardice.

I enjoyed watching Sin's journey from denial to acceptance, and his emotional growth and closure. Our menacing mercenary truly turns into a cinnamon roll. One that would destroy everything to keep her safe. This book is a fantastic sci-fi romance with drama, danger, and connection that leaves you cheering for their Happily Ever After!.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Carole · Rating 4 out of 5]

Tempted by the Alien Mercenary is book seven in the Monster Mercenary Mates series bringing readers another entertaining Sci-Fi Romance.
Ancient warrior Sineater has been part of the Varakartoom crew for many years but of late since the advent of human mates bringing feelings of happiness and contentment to some of his crew mates it has caused his symbiont Val to hunger from lack of dark feelings to feed on. When an opportunity to search a planet where crime lord Jalima may have a hidden stronghold he takes the mission.
Maybe there his symbiont will be able to assuage it’s hunger.
What he does find is a derelict human vessel with stasis pods and their deceased occupants, all except for one, with the vessels Captain Frederique Moretti.
I loved this newest book which was chock full of action, adventure, surprises, danger, intrigue, spice, mate bonding, emotion, wonderful writing, and characters.
It was quite a journey to that HEA!.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Sheree · Rating 5 out of 5]

Book Seven of the Monster Mercenary Mates series and we finally have the story of the Sineater (Sin) – the dark, looming presence on the Varakartoom who relies on dark emotions to survive. Unfortunately for the Sineater all the happily mated couples have him surrounded by positive emotions and he is starving along with his symbiont. Their connection is fraying, and he doesn’t know how to fix it.
Whilst on a mission he meets Frederique, a human from a long-lost mission, who has been stuck in stasis on a desolate planet. Sin finds himself feeling – more than he has in centuries – and desperately wishing for the stubborn human who is not afraid of him. The chemistry is intense between the two. Frederique accepts Sin for who he is, being one of the few beings in the galaxy who knows what he is. They deserve the happiest of endings and I’m happy to say the author has done their story justice.
I love this series, the characters are so varied, and the world building is top tier. Each story is as unique as the characters. The author is a must read for me – all her series are fantastic.

[Guylande Jeudy · Rating 3 out of 5]

Overall, this was a good read and a strong addition to the series, and it was especially satisfying to finally get Sin’s story. He had always been portrayed as scary, isolated, and distant, with little interaction with the crew, so seeing him take center stage added real depth to his character. Exploring what drives him beneath the fear, hunger, and loneliness made his arc feel meaningful and long overdue.

It’s true when they say everyone has a match, and Frederique was the perfect one for Sin. Having survived betrayal herself, she was strong enough to stand beside him rather than fear him, and their connection felt earned instead of forced. Watching two damaged, isolated characters find understanding in each other added emotional weight and made their pairing believable, compelling, and deeply satisfying for the series as a whole.

I received an advance review copy for free, and I am leaving this review voluntarily.

[Ingrid · Rating 5 out of 5]

This alien romance is the seventh book in a series with recurring characters, but it can easily be read as a standalone. The author provides enough context to enjoy the story without having read the previous books, while longtime readers will appreciate seeing familiar faces again.

The plot is well developed and engaging, and the characters feel layered and believable. Although there is a power imbalance between the leads, the female main character clearly holds her ground, which makes the dynamic feel balanced and satisfying rather than uncomfortable.

Overall, this is a strong addition to the series and a very enjoyable alien romance. Whether you’re new to the world or already familiar with it, this book is well worth reading.

I received a free copy of this book via Booksprout and am voluntarily leaving a review.

[Amanda Lutterman · Rating 4 out of 5]

I’m giving this four stars, but I'll admit I went into it biased against "Sin" because I always thought he was mean. While learning his story helped me understand his struggles, he still isn't quite my cup of tea. Robin O'Connor usually writes very loving, protective, and possessive heroes, and while he eventually met those standards, there were times his cruelty was hard to stomach.

I almost DNF'd this book because of how mean he was at times, specifically the first time they were intimate together, where he seemed to want to hurt her just to prove a point. While he mostly redeemed himself by the end, some of his actions were hard to forgive. Also, I just couldn't get behind the heroine's name, Frederique. It was a good read, but definitely not a five-star favorite for me.

I received an advance review copy for free, and I am leaving this review voluntarily.

[Genevieve · Rating 5 out of 5]

Given than Sin and his symbiont feed off of negative emotions, I was dying to know how this fated mating would resolve. Would the mate bond heal them, would Frederique be his fated mate because she would always carry the pain of waking 700 years after her mission began? How would they encounter each other?

All of these questions were answered *most* satisfactorily. The pacing on this entry in the series was slower and more character driven than others, but there was plenty of action to keep things moving. Are there a few questions remaining? Most definitely… but if I told you what they are I'd spoil some of the mystery. I'll give you one hint though - it reminds me a bit of that old movie The Thing.

TW for one scene with DubCon

I received an advance review copy for free, and I am leaving this review voluntarily.

[Mood in Between pages · Rating 5 out of 5]

I have followed the series since Book 1. The Sineater has been pictured and painted as dark, scary, and the most unapproachable of the crew—yet undoubtedly loyal. To be able to read his own story is a treat. I love how he was paired with Fredrique. That bossy energy of hers; the two of them have made their story even more exciting. And listen—Chapter 21 is fire! 🔥 ... I love a good action book. The thrill and the excitement?! Perfect! I love it. And of course, the ever-cool Varakartoom crew! It's great to see the crew getting bigger, stronger, more tactical because of their mates, their family—their growing family—as well as the united vision they shared and the justice they're fighting for. I can't wait for them to finally face Jalima! Hands down!