Variable Onset is a combination of serial killer suspense with plenty of science and a slow burn romance between undercover agents. The thing is Lincoln and Carter really weren't together for long enough to call it a slow burn, but it had that feel about it. The mystery wasn't all that mysterious but it was still entertaining and the pacing was good, so it wasn't hard to stick with it even after I figured out the whodunit. In the end, there were things I liked and disliked about both aspects of this one, but when it came down to it, this one isn't something I'd read again, but it was worth the once-through.

I’ve had this on my kindle for a while and couldn’t ever get into it. There is a lot going on and a lot of characters and it was hard to keep up with. I decided to go the audio route since I could get it from the library. That didn’t help. The vocal performance was fairly monotone…to the point I had a hard time distinguishing between characters.

The romance takes a back seat to the mystery, which is fine, except if you want me to believe these two are soulmates…or whatever they are. While they have known each other for eight years, there were several between when they saw each other. I could tell they were attracted to each other but never bought the story of them together.

The plot to the mystery was interesting – torturing and killing people through their fears – but didn’t keep my interest all that much.

After reading the Irish and Whiskey and Trouble Brewing series and loving them, I was disappointed in this one.

Variable Onset wasn’t what I expected, but it was still a thrilling and fast paced mystery/ romance. The dynamic of a small town at the center of a high-stake murder investigation, was intriguing and kept me on my toes.

The story is centered on two FBI agents who are pushed together in order to catch a serial killer known as Dr. Fear. Upon first reading that name, I admit I had to laugh. It was just too cheesy and took away a bit of the suspense.

I started this book expecting a bit of spice, and I got a slow burn with a lot of will they, won’t they. Primarily, Variable Onset is a thriller, with sprinklings of romance. Once I understood what I was getting I didn’t really mind. The character development was strong despite the relationship being slow and there were many delightful characters woven into the story that enhanced the plot.

Perhaps one of my favorite things about reading LGBTQ+ romances, is when the gender of the characters isn’t really talked about, and the surrounding world is in complete acceptance. Stories with homophobia, coming out, and a focus on what it means to be in a LGBTQ+ relationship are so important and they all have their place, but sometimes I want a story that can take me away from all that realism, and simply accept the characters for who they are. Reyne does an excellent job of weaving small instances of these topics without putting a lot of focus on them.

Overall I liked Variable Onset, and would absolutely read future releases from Reyne.

3.5 Stars.

VARIABLE ONSET by Layla Rayne is a standalone but I would love to see it become a series. Lincoln and Carter are just amazing together! Lincoln is an agent and a professor at Quantico and Carter took his class eight years ago, making quite the impression on Lincoln. Now they are thrown together again when they go undercover to catch a serial killer.

This story has so many twists and turns in it and I loved every word! For myself, it was never clear just who the killer was, not until it was spelled out for me. And I love that! To be kept guessing right to the end, when it focuses on different characters and each one of them could be the killer, was simply brilliant.

Carter and Lincoln are the perfect pair although they have their own concerns about their relationship. The biggest being is it real or just part of the cover? I thought it was really well written and loved the slow burn aspect of it, even if Carter didn't!! Nothing is rushed in here and it all fits perfectly together.

Like I said, I would love to see this turn into a series but, failing that, I'd just be happy to read more by this amazing author. Highly recommended by me.

* A copy of this book was provided to me with no requirements for a review. I voluntarily read this book, and the comments here are my honest opinion. *

Merissa
Archaeolibrarian - I Dig Good Books!

The premise of this book had all the makings for being a story that I loved. There’s a serial killer on the loose and the cops are not sure if it’s a copy cat or the original killer that was never caught many years ago. So they decide to bring in an expert on the original killer into the investigation to try and rescue the missing people before they die. This is also a student/teacher romance but that comes to fruition years later.

I wanted to like this book more than I actually did. I think overall what made me not love this book is the pacing. It’s quite slow, the mystery isn’t really thrilling, there’s not enough danger throughout. I felt like it delivered a bit of bland romance as well as bland mystery. It had so much potential but it felt a bit boring in the end.

That being said, I loved how the student/teacher angle was handled as well as the age difference. It gave these two the opportunity to reconnect and finally act on things that they never even hinted at.

I still liked it enough, even if it wasn’t memorable. But it hasn’t left me itching to pick up the next Layla Reyne book. And I have a few on my TBR.

Brilliant book. It was so different from her other series that I adored and I loved it. Reyne's characters are so wonderfully diverse and intriguing I can't help but fall into their stories. This one was no different. I look forward to more and can't wait to dive in. If you enjoy MM romance this author can deliver.

I liked this more than I thought I would. Romantic suspense isn’t my usual jam but I like Layla Reyne’s writing. I liked that Carter and Lincoln had a history together and how they still felt a connection despite the years. It was more of a slow burn that I prefer, but otherwise I thought the plot was engaging, if a bit scary and dark given the subject matter. I had no idea who Dr. Fear was until the characters did, so that was fun.

Thank you Carina Press and NetGalley for the ARC!

For some reason, I just could not get into this book. I've tried multiple times, but I just kept on being distracted. I don't know why. This book was not for me.

When the serial killer known as Dr. Fear seemingly reemerges after a cooling-off period, Special Agent Lincoln Monroe wants on the case. He knows his research on the calculating criminal, who targets couples and uses their worst fears to kill them, could prove invaluable. But nothing can prepare Lincoln for the agent waiting for him in Apex, Virginia: a brash and cocky former student. Carter Warren is everything Lincoln is not, and somehow everything he wants. And they’ll be going undercover. As newlyweds. For Carter, seeing Lincoln again—and flustered to boot—pokes his raging bear of a crush something fierce. He thinks posing as lovers will provide the perfect bait for Dr. Fear. But pretending to be married forces them to confront fears of their own…like giving in to the very real chemistry between them. With evidence pointing to the possibility of a copycat killer, Lincoln and Carter will have to race to separate truth from fiction. But when another couple goes missing, finding the killer will test every ounce of their training, skills and the strength of their bond like never before.
This was a pretty good book. It was heavy on the mystery and plot, which I like. I really liked both Carter and Lincoln as they unraveled the mystery. I recommend.
**I voluntarily read and reviewed this book

4.5 Stars
FBI Academy forensic genealogy professor and Agent Lincoln Monroe is an out bisexual caregiver for his teen daughter. He has a great relationship with his ex-wife, a globe-trotting state department employee and his sister who babysits his daughter if he goes on assignment. Lincoln's thesis work was profiling Dr. Fear, a serial killer that captured random couples and subjected them to their worst fears for 40 hours, or until they died--which they all had. He's been active for 25 years, and never caught, but now it seems a copy cat has kidnapped a senator's daughter and partner, and Lincoln is pressed into active duty. The senator, a former agent, was Lincoln's mentor and the former lead investigator of the Dr. Fear crimes.

Lincoln is an introvert and suffers intense stage fright and fear of fire. He's awkward and goofy, and not ready to be paired with a former Academy student who pushed all his buttons in class eight years ago, Special Agent Carter Warren. Carter was in the western Virginia mountains looking up old wrecks to find his missing birth parents when he found a connection to the Dr. Fear victims. He's arranged a cover story for himself and Lincoln in winter wonderland Apex, Virginia, where they will have unimpeded access to police and genealogical records to help find not only the copy cat, but also the true Dr. Fear. But, uh, they are posing as husbands, much to Lincoln's discomfort.

Carter has had a crush on his former professor since that very first class, and he's not beyond having some liberties, if time allows. Not that it really does, with the clock ticking on the missing couple. Their endeavors are hampered by lack of familiarity with the small town folks, oh, and being attacked by crazies and the police department getting firebombed. While one case gets wrapped, two more pop up and the spotlight seems to shine on either the former, or current, police chief--who happen to be lifelong Apex residents...and brothers. When local residents are kidnapped, it's up to some amazing detective work, involving the bells and whistles of forensic science and good ol' library research, to bring this killer to justice.

This is a fantastic romantic suspense, with two MCs that have both tremendous respect and attraction for the other. Lincoln and Carter are great guys, who make the best of the tension, but never let their professionalism slide. It's a total slow burn on the romance, while these men devote themselves to overcoming all the obstacles to find the killers at-large. There were moments of levity, especially regarding Lincoln's self-deprecating humor and Carter's mooning over his crush. And those also brought some nice tender moments, as these men bonded over their deep-seated insecurities. It's a standalone romance, but I'd read another book with these two if it came available.

Special Agent Lincoln Monroe has been teaching new FBI agents at Quantico for the last ten years, but his speciality is forensic genealogy. When the serial killer known as Dr. Fear strikes again, Lincoln is brought in on the case, as he has done extensive research on the killer. Dr. Fear kidnaps couples and uses their worst fears to kill them. His killing sprees come in waves and the FBI has been unable to catch him, or even find many leads. But now, it appears that another agent has found a connection to Dr. Fear in the small university town of Apex, Virginia, so Lincoln is being sent in to help out.

Lincoln is surprised to be matched up with his former student, the cocky and confident Carter Warren. Lincoln definitely was drawn to Carter when they met in class, and it turns out Carter was interested in him as well. Now, not only are the men working together, but they are posing as a married couple to better draw the attention of Dr. Fear as they dig further into the case.

As Lincoln and Carter work together, that old attraction comes flaring back for both men. But time is not on their side and the investigation is paramount in their minds. As they dig into the records and meet prominent members of the small town, Carter and Lincoln begin to learn more about Dr. Fear’s patterns and the leads begin to grow. It seems like they may be starting to figure out Dr. Fear’s motivation, bits about their past, and even some leads on their identity. But even as the men make progress, Dr. Fear seems to be a step ahead. Now Lincoln and Carter must fight with all they have to stop a killer before more people end up dead — including themselves.

Variable Onset is a fabulous suspense that kept me eagerly turning pages as I dug into the exciting story. I have always enjoyed Layla Reyne’s romantic suspense books, but this story really takes things up a notch in terms of the mystery side of things. Here we get into the nitty gritty of the investigation and it is clear Reyne has done her research as the details just pop throughout the case. Carter is an excellent undercover agent who excels at disappearing into his cover and is able to finesse his suspects and witnesses as he digs into the case. Lincoln is an expert at forensic genealogy and is able to pull tiny details seemingly out of nowhere to build leads and find buried connections. Reyne really takes the time to highlight the investigative process here and I was totally engrossed in the story as I followed along with the case. There is a dark, twistiness here as we delve into the mystery and slowly the pieces all come together. This isn’t necessarily a big flashy suspense story (though there are some very exciting and scary moments), it’s more of an old-fashioned investigative thriller as the men piece together the case and slowly discover the secrets behind Dr. Fear. I found it fascinating and really compelling.

I also really loved Carter and Lincoln together. The men have a background in that they used to be student and teacher, and we know from the start that Carter was quite taken with Lincoln. Their lives weren’t in a place to even consider pursuing anything, but there is still something simmering for both men. The fake relationship aspect of the story brings in some interesting dynamics as the men spend time together pretending to be married. Even as they start falling for one another more intensely, there are always questions in their mind about how much of this is for show and what is real. This is a slow burn story and most of the focus is on the case, rather than the romance, but it builds nicely throughout. The guys are honest with one another about how they are feeling, but they are in different places in life (and Lincoln has a teenaged daughter to think about), not to mention that they are racing against time to catch a killer. But there is a lovely dynamic between the men. Carter has a sense of fun and playfulness that brings Lincoln out of his shell and they bring out the best in each other. We see this particularly as Dr. Fear zeros in on the men and they have to give each other strength to handle the pressure.

So I found this a really exciting and well done suspense. The mystery is really engaging and Reyne does a great job giving us a look behind the curtain at this type of investigation. I really enjoyed the slowly simmering romance between Carter and Lincoln and loved the way things all came together. So if you enjoy mystery/suspense, I can definitely recommend Variable Onset.

First and foremost, Variable Onset is a mystery novel. Yes, there is an eventual romance, but it’s very much slow burn and background to the overall story. I don’t say this to scare you away, because I seriously loved this book and think everyone should read it. Special Agent Lincoln Monroe is a professor with years of research on the serial killer Dr. Fear. His former student and current field agent, Carter Warren, has a new lead on the killer, and the two of them go undercover as husbands in order to learn more.

I find books about serial killers to be fascinating – what makes them tick? Why do they choose their victims? Where do they come from? All of these were questions I had about Dr. Fear, as did Lincoln and Carter, of course, who are desperate to stop him once and for all…except now there might be a copycat killer involved too.

I loved both Lincoln and Carter. They are definitely different in a lot of ways, but they work well together and bring out the best in one another. There are obvious sparks between the two – and now that they aren’t professor and student, they can finally act on them. And they do. Not anything too steamy during the case, but they are slowly growing attached and I loved watching them learn to really trust each other.

I don’t know if Variable Onset will be a series or not, but I kind of hope we can get more cases with Lincoln and Carter!


Dr. Fear was a really intriguing serial killer in Variable Onset. He kidnaps people and uses their biggest fears against them – the dark, fire, etc. What he leaves behind is a prescription detailing what the person is most afraid of, aka Dr. Fear. I loved “working” the case with Carter and Lincoln and I didn’t piece together what was happening or who was all behind it until the guys did.

When Carter stumbles on a lead to catch serial killer, Dr. Fear, while searching for details on his own past, he requests the help of his former professor and special agent, Lincoln Monroe, who he has harbored a crush for ever since they met in Lincoln’s classroom. The two go undercover as husbands in the small town of Apex to hunt and lure out Dr. Fear and what they believe to be a copycat killer.
I loved these guys. They each have past issues they are dealing with – Lincoln with his crippling performance anxiety, and Carter with his fear of never being good enough stemming from his mysterious childhood in foster care. Of course, these are ideal issues for Dr. Fear to exploit. While they search for clues, they must face Lincoln’s problem in the course of their undercover work, while Carter’s issues are dealt with a bit later on. Regardless, they are not glossed over, and both know they must be dealt with in order for them to have a relationship.
I enjoyed the slow burn in this one. They don’t just jump each other even though the chemistry is obviously front and center. Thankfully, they put their relationship, physical or otherwise, on the back burner while they take care of solving the mystery and saving lives. We get to see beyond the cocky and confident façade to the vulnerable man inside, as well as the strong silent type who shows a flirty side. They come from completely different family backgrounds, both past and present, but it is clear they are exactly what each of the needs.
This was another enjoyable hit for me from Ms. Reyne. I’m a bit disappointed we won’t be seeing these guys again, but I am looking forward to whatever she comes up with next.

Ths was incredible. Not only the plot was gripping at all times (and the depth of the investigation the author must have done to get to that detailed development), but also the characters were unique and so much fun to read about!

One special mention to the pacing for the romantic subplot, because this was such a delightful slowburn with just the right crumbs scattered evenly throughout

Arc provided by Netgalley in exchange of an honest review.

3.5

This is a detective romance story between 2 men that had the hots for each other 8 years before the book started. So, technically, for them it's a slow burn. For the reader is more like insta attraction. We didn't get any natural build up to their relationship, as soon as they see each other they're getting hard and bothered and I didn't really appreciate that. While their relationship is very sweet towards the end, that beginning for their relationship just bothered me. They also did not read like 40 and 30 years old, they read more like 20 years old.

As for the detective part, while it definitely looks like the author did her research, some things were very questionable and unrealistic to the point of absurdity. I know it's fiction and I don't claim to know everything about criminalistic but still.

I would recommend but it's a one time enjoyment kind of book.

Okay, let's start with YES!!!! I love Layla Reyne's books. This author does suspense so well!!! This book says it is a stand-alone, and I'm not sure with how this book ended how the author could make this into a series, but please figure it out!I really enjoyed these two characters, both together, and separate. Lincoln is such a nerd, a true academic, but clearly adores his family. And had a bit of a crush on his student. Meanwhile, Carter is his exact opposite, bold and cocky, and although he wants to go after what he's been wanting for years, he is patient, and waits. They worked together so well, finding the clues they needed to find their serial killer, but also to find the answers to a long held secret of Carter's...which guaranteed, it will make you cry.I really would like to see these two work together again. I'd love to see this author take this series and run with it. I mean...if the author is asking. :)4 pieces of eye candy

Variable Onset is a combination of serial killer suspense with plenty of science and a slow burn romance between undercover agents. The thing is Lincoln and Carter really weren't together for long enough to call it a slow burn, but it had that feel about it. The mystery wasn't all that mysterious but it was still entertaining and the pacing was good, so it wasn't hard to stick with it even after I figured out the whodunit. In the end, there were things I liked and disliked about both aspects of this one, but when it came down to it, this one isn't something I'd read again, but it was worth the once-through.

4.5 - 5 stars...

Have you ever started reading a book and knew that you weren’t going to be happy when it ended? That was me at just 32% into Variable Onset. I knew I wasn’t going to be happy that this was a standalone. I loved the tension and connection between Carter and Lincoln. It was definitely a slow burn, but it didn’t feel like anything was missing. The mystery and suspense drove this story – the romantic tension and history between these two characters was a bonus and by the time the story was over I most definitely wanted more. #evilauthor

The supporting characters were great too and it was sometimes hard to tell the good guys from the bad. There was one character that I was relieved to find was one of the good guys. (Who I also wouldn’t mind discovering in a future book somewhere, somehow 😉 ) ❤ I suppose there were some readers who picked up on the identity of Dr. Fear, but I wasn’t one of them. I pretty much caught on at about the time Carter and Lincoln did. There were a lot of players in Variable Onset along with a lot of connections. More than enough tension and suspense to keep the pages turning. I even liked the serial killer’s unique way he preyed on his victims. Having a serial killer lurking around was bad enough, but knowing that he used his victim’s worst fears against them was horrifying. Not just that but how close he had to get to them before their capture to know what those fears were… *shivers*

If you’re looking for a hot and heavy romance, Variable Onset isn’t it. If you’re looking for a great suspense with romantic tension between characters with a history, who find themselves in a situation that involves them to be in very close proximity, where it’s hard to ignore their attraction to each other that results in a VERY slow burn romance… Yeah, I think you get the picture.

If Variable Onset is your first Layla Reyne book, you need to treat yourself to her other series. I started with Agents Irish and Whiskey and haven’t looked back since. 😉

Variable onset is an incredible twist on a mystery romance that keeps you engaged right to the end. Reyne weaves interesting science and intriguing characters into a mystery that feels as imperative as the romance brewing between Lincoln Monroe and his former FBI academy student Carter Warren.

Another enjoyable read by Layla. She’s quickly becoming an auto buy author for me. Looking floreare for her next book.