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Only The Devil Knows

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Criminal Delights

My name is Max, but people call me The London Whipper. I’ve been silent for many years. Now I’m ready to make my final move.

Only The Devil Knows follows the people trapped within my web of lies:

Nathaniel Harris, a psychologist who works with the criminally insane.

Genevieve Knight, the Chief Inspector determined to find me once and for all.

Wyatt Pearson, the beautiful boy who believes I’m a hero instead of a cold-blooded murderer.

Each of these people has one thing in common—they all want me. But what happens when my whip tangles around them and distorts everything they believe to be true?

I’ve kept my identity under wraps… until now. It’s time to show the public what I’ve been working on. After all, what’s a serial killer if he doesn’t have some artistic flair and his favourite boy at his side?

This book is part of CRIMINAL DELIGHTS. Each novel can be read as a standalone and contains a dark M/M romance.
Warning: These books are for adult readers who enjoy stories where lines between right and wrong get blurry. High heat, twisted and tantalizing, these are not for the fainthearted.

196 pages, Kindle Edition

First published March 1, 2019

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About the author

Katze Snow

8 books242 followers
After leaving school and renting a crummy flat at sixteen, bestselling author Katze Snow lives in Scotland with her wolf-dog and furbabies. Don't be fooled by how cute she looks out on the outside. Katze's writing is dark, twisted, and takes depravity to a whole new level.

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5 stars
175 (36%)
4 stars
156 (32%)
3 stars
101 (20%)
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33 (6%)
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21 (4%)
Displaying 1 - 30 of 106 reviews
Profile Image for len ❀.
381 reviews4,238 followers
May 22, 2022
nothing like opening this little story on a sunday night with the first pages consisting of a naked man hanging on the brink of death, full of blood, splayed and beaten, as his killer gets aroused at his sight.

TW: rape, violence, death

so here we have:

🖤 a man most likely in his 40s who’s been murdering for two decades. known as the london whipper, he attracts young men, only to rape, torture, and then kills them for his own pleasure. he uses his preys blood mixed with paint to make art and finds bliss at peoples suffering.
🖤 his 20 year old “boy” who worships every step his Sir steps on and gets aroused from violence inflicted on him—slapping, whipping, choking, punching, and humiliation. he lives through his master’s control, violence, and orders, always being available to be pleasured and used. all he wants is to become his masterpiece. little does he know what his Sir has in stock for him instead.

a masochist and sadist, a true match made in hell <3

He looks up at me, his eyes shining, fucking beautiful. I slap him in the face, leaving another handprint on his pale cheek. Tears well in his eyes from the impact, and another surge of pleasure.
So. Fucking. Beautiful.


🖤 a clinical psychologist who’s discovering he isn’t who he thinks he is and realizes he also may he fucked in the head
🖤 and a police officer who’s been trying to find the london whipper for more than two decades after the pain he caused her

i don’t read dark romance. at all. in fact, i envy some of my close friends who do. something about morality being questioned and good vs evil being indistinguishable. granted, this isn’t a story for everyone, but i enjoyed it. a lot, actually. that being said, this was completely out of my comfort zone. i started it on a whim after submitting my very last final of the semester. i had an idea of what i was getting myself into, but also wasn’t entirely “prepared.” still, i found myself even laughing at some of the scenes, which i’d normally be disgusted by. violence is a main plot device used in this, but it moves the story forward to show the reader what the characters are trying to achieve. whether it’s max and wyatt having rough (consensual) sex or max inflicting violence on someone else, it only adds to the goal max is trying to get to: a display of his canvases as a present for his boy’s 21st birthday. it’s gritty, dark, and descriptive.

He strikes me again, and it scores the skin on my abdomen. I see stars for a moment. It’s like a blissful dream come true. I look down so I can see the blood and tears well into my eyes. It’s beautiful. He’s making me beautiful. He’s transforming me.


psychologically, it was really interesting to see the different point of views because i thought it showed how differently the characters were fucked in the head in different ways. the story follows a timeline that felt consistent and for me, there wasn’t ever a part in it that felt unnecessary or boring. i’m also a very oblivious person and cannot for the life of me predict anything, which i prefer. i would rather not predict stories because being right usually falters my enjoyment. whether the twist shows up as an interest point that increases the adrenaline the story starts to give, it can be annoying. luckily, what i thought would the case here was wrong and i was off. instead, i got a plot twist i didn’t see something. confused i was, but definitely not disappointed at all.

as for the ending, i’m very content with it. nothing better than seeing evil prevail.

He promised me months ago that I would someday be his masterpiece. I ache for him to put me against his canvas and turn me into art. His whip will beautify me, and I’ll be a monument to his delicious cruelty. I yearn for it. I want it so badly that sometimes I get jealous of the people he’s already killed.


read this if you like/are looking for:
🔪 dark mm romance/thriller
🔪 a plot twist you may not see coming, depending on how oblivious you are (like me). even if you find it predictable, i still think the route the story takes is interesting.
🔪 BDSM relationship (masochism and sadism) - max and wyatt have a complete master/slave relationship
🔪 age gap - wyatt is 20, and max is in his 40s

✨buddy read with matilda
Profile Image for Nazanin.
1,182 reviews783 followers
April 29, 2019
4 Stars

Themes: D/s relationship, forbidden love, BDSM, forced proximity Actually this isn’t really a love story and don’t go into it and expecting romance!
Genres: Dark M/M Thriller, Psychological The psychological part was so predictable but it is DARK, proceed with caution!
Heat level: Scorching explicit scenes, rough, consensual So true!
Warning: These books are for adult readers who enjoy stories where lines between right and wrong get blurry. High heat, twisted and tantalizing, these are not for the fainthearted.
Told in multiple POV, 1st person. It’s the third installment in the "Criminal Delights" series but it can be read as a standalone. It’s a quick read. Overall, I liked it and hope you enjoy it as well!
Profile Image for Matilda.
269 reviews2,633 followers
May 16, 2022
3.5 stars 🩸

When I finish, a galaxy of multi-coloured spatters will create a pristine outline of the dying man’s frame. He will be preserved forever in negative, his blood and the paint showcasing the imprint of his body better than any chalk outline.


the hero being a serial killer that creates Jackson Pollock-esk artwork from his victim's blood reminded me of that one criminal minds episode (s8ep13)

that gang would NOT have let the hero get away with killing for 20 years smh



buddy read with elena ❤️‍🔥
Profile Image for Nelly S. (on semi-hiatus).
588 reviews142 followers
May 17, 2022
tw: violence, rape, degradation, forbidden love

“I ache for him to put me against his canvas and turn me into art. His whip will beautify me, and I’ll be a monument to his delicious cruelty. I yearn for it. I want it so badly that sometimes I get jealous of the people he’s already killed.”

— dark m/m thriller
— serial killer/pet boy
— BDSM
— forced proximity
— age gap
— steamy

So I thought I’d read dark romances before…turns out I hadn’t. So this is effed up guys. Like some seriously effed up shit. Like had me questioning my morals for enjoying this shit. Is it disturbing? Yup. Depraved? Extremely. Hot? Guiltily so. Gory? You betcha. But it’s so damned entertaining and will keep you enthralled from start to finish.

So here’s the set up: Max aka The London Whipper, is a serial killer on the loose and has a slavishly devoted pet boy, Wyatt. Nathaniel, a clinical psychologist, and Chief Inspector Genevieve, are on a desperate hunt for the The London Whipper as the body count escalates. There’s an intriguing Dissociative Identity Disorder twist in the plot.

As for the nitty gritty: there’s a lot of violence and gore folks. Yet it never feels gratuitous because it drives the plot forward. Sexual violence is a major part of the killings. And there isn’t much difference between the kind of sexual degradation Max inflicts on his victims and the brutal sex he has with Wyatt. But Wyatt is an enthusiastic participant who craves pain and they’re in an extreme Master/Slave relationship. There is more to the story than just gore and depraved sex however. The mystery is gripping and the writing is good. I definitely recommend it if you’re in the mood for something twisted.
Profile Image for Ro {semi-hiatus}.
275 reviews10 followers
February 23, 2024
this was repulsive fr lmao have read worse but like. my foray back into reading this year has gone down some trails. yeesh. despite the twist being obvious by page 40, i was still into it i guess. as per uuuusual i rooted for the serial killer and idk why i'm like this
Profile Image for Mimi.
2,271 reviews
April 24, 2019
4.5 Amazingly Creepy stars

So far this series is off the chain. Book One takes you down the slippery slope that is the criminally insane and Book Two has you on the cray cray coaster. Now Book Three, Wow what a ride these ladies gave us.

You don't see the twist until it's too late and you're just blown away. I really hope the other 14 books in this Criminal Delights series is just as cray cray, mind blowing and devilishly creepy as the first three. Nice read ladies!!
Profile Image for Kelly.
435 reviews21 followers
April 30, 2019
Arc copy provided by LesCourt
All reviews are voluntary and my honest opinion.

An erotic tapestry painted in blood, and rendered in filth and depravity.
Maxwell is the Whipper, a psychotic serial killer who ties his victims to canvas and dumps paint on their bodies, lashing them with whips, and leaving them for others to find.

His psychosis is the result of developmental issues caused by his uncaring father, and the infidelity of his mother. The Whipper can't stand women, and lashes out. He only uses young and beautiful men to create his masterpieces.

The closest thing he has to love is a young man named Wyatt who is just as depraved and cynical as Maxwell.

The book is fascinating from start to finish, it's an entertaining if dark and gritty look into the mind of a serial killer. It's masochism taken to an extreme. Both Maxwell and Wyatt are broken creatures who find solace with each other, their wants and needs far outside the realm of normal societal boundaries.


This book is not for the faint of heart. If you're into criminals and serial killers, this will probably interest you, but it's definitely bloody and obscene in ways that may make some readers uncomfortable. On the other hand, I enjoyed it immensely, and probably will reread it at some point in the future.

Includes unsafe but consensual BDSM practices. Includes graphic descriptions of murder and violation of the whipper's victims.

Rating 4/5 stars.
Profile Image for Kim BookJunkie ~ Editor & Proofreader.
2,046 reviews56 followers
August 14, 2019
4.5 stars

Max (known by the press and police as “The Whipper”) is a sadistic, psychopathic, murdering Dominant.
“I’ve always told myself that if I’m going to hell, I might as well enjoy the fucking ride.”

Max’s “boy“ Wyatt is his overly willing, masochistic sub. They enjoy their “games“ which include torturing and raping male victims in extremely creative, gruesome, artistic ways.
”An annoyed Max is a sight to behold, and he gets violent once he’s angry. My arse tingles as I think about it. I want to feel his hands around my throat, choking me again. I want him to hurt me. Nothing else feels so good.”

Doctor Nathaniel Harris is a Psychologist who specializes in working with the criminally insane. He’s been called in to help profile The Whipper.

Chief Inspector Genevieve Knight is in charge of tracking down The Whipper. The Whipper killed her nephew so it’s not just the job that drives her to catch him.

Max tortures, rapes and kills his victims against a canvas in order to create pieces of art. That’s not where the creativity ends though... there’s nothing predictable about this book and a lot is not what it seems!! I’ve read a ton of dark, dark, dark erotica but was impressed by how gruesome, explicitly disgusting and depraved the torture in this book is! These ladies dug deep!!!! As obvious by the list of the main characters, this book is unique in that we get to see all four perspectives, not just the serial killer or police investors perspective but all of them! And it’s all done in under 200 pages in a concise, easy to read, entertaining manner. If I could, I would give this book 4.5 stars. The first 99.9% is fantastic, but I was disappointed with the ending.
Profile Image for Courtney.
1,210 reviews189 followers
April 18, 2019
I received an Advanced Copy from the Author for an Honest Review.
I Give This Book 5 Stars

Heat: 5/5
Eroticness/Kinkiness: 5/5
Romance: 3.5/5 (not in a bad way! It was there but this is Max we’re talking about XD, it’s there just not upfront LOL)
Suspense:5/5
Drama:5/5
Dark:5/5
To All The ‘No Limit’ Readers, this one is a must read.
It’s so hard to find well written stories like this.

What a great intro!
The very first paragraph, I can literally describe it with one word: PERFECTION

Take note: if you want a readers attention, THAT is how you start a book XD

This book is Super Super Dark and enjoyed every bit of it. Heck it could’ve been Darker and I would still be on board! XD
When I saw how it was going mid way of the book, I was so surprised at the twist cause it was exactly what I was hoping for.

Loved the Ending!
This is a HEA(!!), So There is No ‘Metaphorical’ Tricks.

Would I read more from this Author: Most Definitely! Looking forward to more books like this!
Profile Image for Maze the Amateur Reader.
92 reviews26 followers
March 6, 2021
This was a lot darker than the two previous books but I'm a dark romance junkie so it could've been darker but I would still read it! Lots of bloodshed, choking, slapping/punching, but that's what makes the story more intriguing. Not my favorite in the series but it was still a good read with satisying ending.
Profile Image for Armand.
184 reviews31 followers
December 30, 2019
A serial killer is on the loose in London literally whipping young men to death. It's been a long time since he started, but now he has a grand plan in store. He tempts the police to catch him in a final game of cat and mouse. Only question is - are they up to the challenge?

Unfortunately, Chief Inspector Knight can't manage to get the requisite emotional distance from the case, which is understandable since years ago a cherished family member was one of the victims. That might have had a hand as to why the case dragged on for two decades tho. One also wishes that the psychologist Dr. Harris weren't so carnally taken up with his charge Wyatt, who can very well be a trojan horse sent by the London Whipper as part of his plans.

I marvel at how inept some of the professionals working on this case were. Just after Knight was almost assaulted by Wyatt in a meeting where he wasn't put in any restraint whatsoever, a doctor who was trying to prise some info from him got close enough to have his ear bitten off. And just after that, an orderly allows this creature to blow him, putting his precious junk within reach of those chompers. I mean - wha? With all of these setbacks, it seems like they would indeed have a hard time pinning down the cunning Max.

There's a twist in the middle that wasn't difficult to figure out, but that doesn't diminish the thrill of this chase. However, I just can't at the utter idiocy of the characters. What a bright, shining mess it all is.

I'm rating this 5/10 or 3 stars out of 5.
Profile Image for Natalie .
3,079 reviews30 followers
February 12, 2021
For me this was the worst one so far and also the most depraved. There wasn’t much mystery, as the culprit was obvious from the first introduction. A serial killer that likes whipping young guys to death and creating art, a closeted psychologist with childhood trauma, a hero worshipper masochist and an investigator that hasn’t had a lead in twenty years and has personal connections to the case. Also friends with the psychologist.

Plenty of sex and killing to the point it feels like it’s there for shock factor. Took a while to get into this one, it felt simple and Max came across as an opportunist snatch and grab. I didn’t get how there were no witnesses, why Gen was on the case or how blind she was. Contains violence, rape, psychological issues, murder and whole bunch of other gross stuff. Straight down the rabbit whole with this one.
This entire review has been hidden because of spoilers.
Profile Image for Marta Filipa.
138 reviews
March 24, 2024
3.75⭐️
Chegou a um ponto em que eu consegui prever qual era plot twist antes de ele acontecer mas mesmo assim aconteceu muita coisa depois que eu não estava à espera...
O max é dos personagens mais perturbadores que eu já li...
Profile Image for Mirjam.
1,819 reviews111 followers
September 9, 2019







I don’t paint with ink. I paint with blood.

This was a fucked up read, it is dark as fuck! And what does it say about me that I absolutely loved it!

Max aka The London Whipper, is seriously deranged “The Whipper is clearly a sexual deviant.”
The story is told from four POVs, alternating between Max, Wyatt, Gen and Nathaniel, creating a thrilling buildup to the big jaw dropper. While their were numerous hints, the confirmation of what I thought, was still mind blowing.


Book 3 in this series is as graphically gruesome and disturbing as it gets, and Max is one crazy motherfucker. But still, I could understand his reasons why. His relationship with Wyatt, while utterly depraved and bloody, is his constant and one that is very important to both of them.


Please, heed the warnings this book comes with, but do not miss out and read it!


Part of the Criminal Delights series. While part of a series, each can de be read as a standalone:
Wrong Way Home - Criminal Delights Taken by K.A. Merikan Devil Next Door - Criminal Delights Obsession by Alex Jane Only The Devil Knows - Criminal Delights Serial Killers by Katze Snow Blood & Bitcoin - Criminal Delights Organized Crime by L.A. Witt Sweating Lies - Criminal Delights Taken (Lies #1) by Emma Jaye Match Grade - Criminal Delights Assassins by G.B. Gordon Splintered - Criminal Delights Obsession by Tal Bauer Love Kills - Criminal Delights Serial Killers by Michael Mandrake Beloved Possession - Criminal Delights Organized Crime by Leona Windwalker Sinner's Ransom - Criminal Delights Taken by M.D. Gregory It's in My Blood - Criminal Delights Obsession by Sean Azinsalt By Way of Pain - Criminal Delights Assassins by J.M. Dabney Hunters and Killers - Criminal Delights Serial Killers by Dora Esquivel Cold Light - Criminal Delights Assassins by Michelle Frost To Have and to Hold - Criminal Delights Taken by Abigail Kade Splitting Lies - Criminal Delights Taken (Lies #2) by Emma Jaye
Profile Image for **Kαчcєє**.
680 reviews17 followers
Shelved as 'dnf'
March 2, 2021
DNF 12%

The first person present tense didn’t agree with me.
And I didn’t care for the MC
41 reviews1 follower
April 23, 2019
The darkness within

This book is not for the faint hearted. It is well written and totally unpredictable. There is blood and violence and it takes you deep into the mind of a serial killer. You know you've come across a great author when they make the bad guy so likeable!
Profile Image for  ♥ Rebecca ♥.
1,458 reviews471 followers
May 1, 2019
1. Wrong Way Home ★★★★
2. Devil Next Door ★
3. Only The Devil Knows ★★★★

I really enjoyed this book. It was like a murder mystery more than anything, a who-done-it from the POV of the the 'who', among others. I totally saw the twist coming from a mile away though. It was so obvious that I was starting to think it was a red herring. It didn't detract from my enjoyment of the book though. I was really invested in the story and anxious to find out how it would end.

This was still really quite dark, like Devil Next Door, but luckily, in just such a way that I could still enjoy it. The main reason for that is there was less violence on the page, lots of people still died and it was fairly violent, but the worst of it was left to our imagination. Also, any violence towards Wyatt was consensual, and the characters were interesting enough to compensate. Not that this book's baddie was not as bad as Devil Next Door's baddie. They are both equally evil, but I just think that this book and its characters were better written.

I do have a couple of complaints though. There wasn’t actually that much romance, and I wasn't really a big fan of the ending or of Max. It can still be considered an HEA, but I would have preferred if .

So on my made up Dark Romance scale this is how dark I would rate the Criminal Delights books so far:

1. Wrong Way Home 4/10
2. Devil Next Door 10/10
3. Only the Devil Knows 10/10
Profile Image for nohe;.
181 reviews15 followers
June 1, 2024
Yo sigo sin saber como puntuar este libro y no sé, o sea sí se que son libros para no tomarse en serio, para leer rápido de una sentada, pero hay ciertas situaciones que agradezco hubiese tenido advertencias de contenido, pero aún así, no sé que pensar.

Le daré dos estrellas porque creo que la forma en que supieron llevar el "giro" central del libro me gustó, no me lo esperaba. Al haber cuatro narradores y ser dark romance yo me esperaba una relación poliamorosa perturbadora, pues en esta saga creo que todo es posible, pero no esperé lo que pasó y eso sí me gustó, aunque bueno, creo fervientemente que estos libros no son para cualquiera y este especialmente es un poco pesado.
253 reviews
April 19, 2019
**Read the disclaimers before diving in to this book**

4.5* Only the Devil Knows is written by Katze Snow and Tiegan Clyne and is a part of the the Criminal Delights series by a group of authors (each book is a standalone). This book follows four characters - Max, Wyatt, Nathaniel, and Genevieve on the search for the identity of the serial killer, "The London Whipper".

I loved this story! I've been looking for a book that is a bit of a mind-f**k for a while and this definitely has that factor. It's suspenseful, high heat, and that twist to find out who "The London Whipper" is was very well done. I really liked seeing this story through the four different POVs as they all bring something new to the table. I know it's only a single story, but I would really like there to be a sequel to this. Going back to re-read all of the little details I missed leading up to the plot twist ;)

"That, truly, will be my masterpiece. My proudest accomplishment. My perfect boy."
Profile Image for Nicole.
208 reviews
April 22, 2019
A mind-blowing read, not for the faint of heart

Nothing could have prepared me for the twists and turns this book has in store. I found the plot to be gripping, heart pounding, twisted and all kinds of dark. Snow and Clyne have given us a heart pounding, knee jerking, edge of your seat tale that I have never had the pleasure to read. The characters, all amazing in their own ways, are well written and keep you guessing. This is really not a fluffy read, but rather earthy and gritty with a lot of tension of many varieties. Definitely not one to be missed.
Profile Image for Penny.
854 reviews11 followers
April 23, 2019
Woah I really freaking enjoyed reading this story.
Only The Devil Knows is a dark, twisted, violent and disturbing (but in the best possible way) tale. There are some twists and turns I didn’t see coming but once that happened I thought about the clues that were there and it all made sense.
This book is seriously good, and if you like a MM dom/sub relationship, violence, plenty of dark elements and a bit of horror this is definitely the one for you.
I am seriously hoping that there will be more books so we can see more of Max and Wyatt.
Profile Image for Nichole.
633 reviews
April 23, 2019
This book was deliciously dark. If that is not your type of thing then this book is not for you. If you like serial killers, a bit of a twist, and some dark delicious scorchy sex, then you have come to the right place. Does that make me twisted? Maybe, but I just really enjoyed this book. It's so different from the sweet loveable characters. It's got grit and sucks you in. I haven't read all the others in this series before but now I am definitely intreged. This was all the stars from me.
Profile Image for Katerina Ross.
Author 7 books16 followers
April 21, 2019
Max is convinced that all art is pain and that there is something inexplicably erotic about watching a person die. He's playing a game no one understands—even his devoted, masochistic apprentice. Will someone catch him? Or will he have his own version of a happy ending?

This book was a bit too gory for me, but you might like it if you're looking for something VERY dark—Jack the Ripper kind of dark!
74 reviews5 followers
April 22, 2019
Holy smoke balls

READ THE DAMN WARNINGS! This book is the best in the series so for! I am in love with all the characters but Max is mine I claim him lmao. I can’t say to much I don’t want to give away anything but please pick up this book it is amazing!!!!!!! Tiegan And Katze are amazing! You won’t be disappointed!
Profile Image for Sayaka.
6 reviews
August 13, 2020
I really struggled to rate this book. It’s not that it’s a bad book, I just didn’t enjoy it and it wasn’t what I expected. I have been really enjoying this series and this book didn’t fit in with the rest.
Profile Image for Myriam.
371 reviews62 followers
Shelved as 'nope'
April 30, 2019
Oh hell no. 1st person AND the word 'arse' in like the first 20 words? NOPE.
Profile Image for Eve.
550 reviews42 followers
Shelved as 'did-not-finish'
July 10, 2020
Got 33% through and still not hooked. Bailing.
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