Thank you to NetGalley and Houghton Mifflin Harcourt for this reader's copy. In exchange, I am providing an honest review.

Hell yes! Wow, was this g.o.o.d.

Detective Sam Porter is on leave but early one morning gets a phone call from his partner promising that Sam is going to want to see this traffic accident victim. Sam is annoyed, he works homicide so traffic accidents aren't his thing AND he's on leave. But Nash promises Sam he needs to see this so he goes. The accident victim happens to be the Four Monkey Killer Sam has been tracking and chasing for the last five years. What luck! Handed to him and his team through a traffic accident. Right? The thing about the 4MK is he lets his victims slowly suffer for about a week before their bodies end up somewhere in the city. He starts with their ear and in the dead man's hand is a box with an ear in it so Porter and his team know the clock is ticking. They've got to figure out who the victim is and then where the victim is before they die from dehydration. Time is of the essence, so much so that Sam doesn't even get reinstated from leave - he just dives right in to getting answers. Found on 4MK's body is a diary meant for Detective Porter to read, in a note to him from beyond the grave (so to speak) 4MK has promised Sam some answers to questions everyone has about this maniac. Can they figure out who the victim is and where the victim is in time or will 4MK claim another life after his own has been extinguished?

Holy smokes was this good. Barker crafted a terrifying villain with a truly terrifying backstory and crafted a compelling good guy in Detective Sam Porter. He also created great secondary characters that really filled in all the gaps between Porter and 4MK, if there were any. I saw a few reviews where readers were annoyed at 4MK's diary entries but I loved them. I didn't mind the flipping back and forth between diary entries and "present-day" at all. It was a way for Barker to give us 4MK's backstory, and I always appreciate a backstory - especially when it's as well-crafted as this one is. This story read FAST and I literally found myself on the edge of my seat a few times while reading it. Barker was able to do with this story and its characters what I love about reading. He wrote it all so well that my mind was able to imagine it all and it was like watching a movie in my mind except I was doing it through reading. Fantastic. Cannot wait to read books 2 and 3 in this series - hurry up library holds!

I wanted to love this book. It had all the components that make a suspense/thriller a true standout, but for some reason I struggled to truly connect. Such is life. I made the difficult decision to set the book aside and move on to something else. Thank you for access to an early copy.

I personally thought this one really didn't live up to the hype. I feel like the plot had trouble keeping my attention, and it was a struggle to finish the book.

One of the twistiest serial killer reads I've ever read!! The author really excels at writing crime fiction , his writing style pulled me in instantly. I would also recommend reading the sequel; it is just as delicious.

3.5 stars. This was a solid serial killer thriller that intrigued me enough to read the next book in the series. The characters could have been flushed out a little better. Often seemed like cardboard cutouts. I really liked the diary parts of the book and seeing how the killer's childhood shaped why he/she was doing the killings. I did think it was strange that it took so long for the police to actually read the diary. That seemed a little far-fetched.

I think I found a new favorite author! Not very often can I say I loved all of the characters, and was completely surprised by where the book ended up.... anxiously awaiting book 2 in the series, as well as looking forward to reading any other books by JD Barker :)

An intensely dark thriller that will send chills down your spine. I was both freaked out and addicted at the same time. I cannot wait for the next book.

This was more like a 3.5 stars. To be honest, I almost added it to my DNF pile and gave up. Once you get past the first chapter, things start to get interesting. I like that it's fast-paced, so it held my interest just long enough to push my way through. (Normally I give up after the first chapter if it doesn't grab my attention)

Worth a read if you like TV series like Blue Bloods or CSI (which I do) 🙂

Seriously dark and twisted! This first book in the 4MK series is amazing. J.D. Barker does a fantastic job sucking you into the mind of a serial killer. I loved the Diary! A very personal touch that I thought took this book to the next level. I’ll gush about the diary in a moment…

The basic framework of your typical serial killer trope is present. We have Porter, the dedicated detective with a troubled past. Nash, his sidekick, and Porter’s faithful loyal team of secondary characters who back Porter in his investigation. Our twisted serial killer, who is dubbed 4MK, with an MO revolving around the premise of the three wise monkeys (here no evil, see no evil, speak no evil), with the addition of the fourth monkey (do no evil).

Porter is on the hunt for 4MK’s latest victim. Unfortunately, it’s rather hard to catch a killer who died right after he took his victim. But even in death 4MK is leading Porter down a rabbit hole; leaving behind an intimate portrait of himself in the form of his Diary.

Initially I thought this may end up being a bit bland. A typical storyline that while enjoyable, wouldn’t blow me away.

However, what drew me in is how we are introduced to the serial killer through his Diary; which was left behind for Porter to find. After years of trying to catch 4MK, the diary is Porter’s closest connection to his nemesis. What starts as a way to gain the insight he needs to find the serial killer’s latest victim becomes an obsession.

The diary is bizarre in the extreme. The beginning gives the impression of a beaver cleaver type family through the eyes of a young 4MK. At least a killer’s version of a beaver cleaver type family! LOL

But it quickly becomes clear that things are much more sinister. We’re held front and center watching an already disturbed mind unravel, creating the gruesome killer that I hate to love. I was both rooting for Porter and connecting emotionally to a batshit crazy killer. It’s a testimate to J.D. Barker’s writing skill that he made me actually kind of love this killer. (even though he’s bound to give someone nighmares! 😉 )

The Fourth Monkey is fast paced and full of twists and turns that make this the most enjoyable thriller I’ve read in a long time.

Houghton Mifflin Harcourt and NetGalley provided me with an electronic copy of The Fourth Monkey.
I was under no obligation to review this book and my opinion was freely given.

The Fourth Monkey delivers on the promise made that it is a "dark and twisting novel". The main character, Detective Sam Porter, has suffered personally but is called in on a death of a suspicious nature. Having been chasing the Four Monkey Killer for over five years, it seems as though his terrorizing of the Chicago area may be at its end. As the clues left behind point to an immediate issue, Sam and the other detectives are in a race against time to conclude their investigation.

The author has done a great job crafting a fully developed main character in Sam Porter. Although I did not feel it was strictly necessary to spend so much time alluding to the circumstances surrounding Sam's personal life, the plot kept up a thrilling and twisting pace throughout. The story took on a life of its own and I found the investigation into the Four Monkey Killer to be very credible and realistic. Detective Sam Porter is a good main character, one who has more story to tell. I would definitely recommend The Fourth Monkey to readers who enjoy a good thriller and I look forward to reading more by author J.D. Barker in the future.

This book was disturbing on so many levels.... but I had to know how it ended and I could not stop reading! I literally cringed and considering stopping so many times, but I'm glad I stuck it out and I definitely recommend- even if I may have nightmares for the foreseeable future.

I am a little late to the party...hanging my head in shame! I have had this on my pile for way to long and certainly wished I had read it sooner. This is one hell of a dark and creepy read and will have your pulse racing until the very end......Love, Love, Loved it!

Set in Chicago we follow the story told from Sam Porter's POV with chapters that alternate with diary extracts from 4MK. Where we get inside the mind of a serial killer, which is something that always interests me. Learning about 4MK childhood and their twisted past which gives some seriously mind blowing character build up. The reader knows from the start of the story that the killer is dead, but leaves one last victim who may still be alive.

Holly Freaking Hell I am beyond excited about this book. This is one fast paced read which I couldn't turn the pages fast enough. J.D Barker definitely knows how to keep the reader on their toes that's for sure. This isn't for the faint hearted and most of you know that I love a dark read. But this is so masterfully crafted you will not believe it until you read it for yourself.

Ticking all the boxes for me this is without a doubt one of my best reads for the year. I cannot recommend it enough, giving it 5 massive stars.

Grab your copy from Amazon now

For awhile, I was left wondering what on earth was the point of somethings, but they came full-circle and while I easily guessed the first twist, I was still thrown through a loop by the second one. I definitely wasn't expecting an ending that'd leave my mouth gaped open

This book definitely reminded me of Se7en and The Silence of the Lambs. It was gruesome, intriguing, fast-paced, and intense. A little over the top at times but that's what made this serial killer thriller more enjoyable. It was interesting, and exciting, how the author depicted the killer through diary entries from the past while the detectives were telling the story from the present. I really enjoyed this book!

A riveting story that sucks you in. It held my interested throughout.

All I can say is WOW! and thank you so much to my dear friend, Kaceey for encouraging me to read this book!  You only told me I don’t know how many times that I needed to read this book and now I know exactly why!!!  5 Thrilling Stars!

THE FOURTH MONKEY (A 4MK Thriller, #1) by J.D. BARKER is a dark, thrilling, chilling, creepy, and suspenseful mystery/thriller/police procedural novel that was a captivating, gripping, and fast-paced read that was extremely hard to put down.  I absolutely loved this one from start to finish as I was stepping into the sadistic mind of this sick and twisted serial killer. There are so many good twists and turns to keep you entertained and on the edge of your seat with all the cat and mouse games that occurs throughout this story between a detective and a serial killer.

The premise of the book involves the four monkeys which I found to be quite interesting.  The four monkeys are Mizaru, covering his eyes, who sees no evil; Kikazaru, covering his ears, who hears no evil; Iwazaru, covering his mouth, who speaks no evil; and the fourth monkey Shizaru, symbolizes the principle of "do no evil".

J.D. BARKER delivers an extremely intense and well-written story here with some cringe worthy scenes that is told through three different perspectives including the serial killer’s backstory by way of diary chapters.  The diary chapters was one of my favorite parts of this story as it really allowed me to get inside the life and mind of this disturbing and creepy character.

I couldn’t help but love Detective Sam Porter's character as he was vulnerable, funny and such a likeable character. I really appreciated the witty banter that ensued between him and Nash as it really helped to ease the tension of the disturbing scenes as they could get a little gory at times.

This book was so exciting, fun and thrilling to read that even had a little bit of horror thrown in to keep me totally engaged and eager to read to see how it was all going to play out.  The ending was unexpected and spectacular which left me wanting more.  So I am so happy to hear that there is a second book coming out and that this is also optioned for both television and film. I can hardly wait!!   Would highly recommend!

In addition to reading this book, I purchased myself a copy of the audiobook and although it took me a little bit to warm-up to the narrator voices, once I did I thoroughly enjoyed Edoardo Ballerini and Graham Winton’s performance and thought they both delivered the perfect voices for the characters.

Thank you so much to NetGalley, Houghton Mifflin Harcourt, and J.D. Barker for the opportunity to read an advanced copy of this book in exchange for a review!!

Wow! I've been meaning to read this one for a while now and finally got around to it. I'm sure glad I did too, because this is one hell of a book!
This tantalizing cat and mouse game played between Porter and The Fourth Monkey Killer is nothing short of brilliance. At times I felt as though I was reading a modern version of an Alfred Hitchcock story.
The flashback segments through the killers diary entries were even more captivating than the story told through the present timeline!
J D Barker has made a huge impression on this reader! I'm a fan!!!

I received an ARC from NetGalley for an honest review.

Woah. This book was bonkers. Can the next one come out tomorrow? Tell me there will be a movie!

I had two hours left of this book, and I told myself I would read for 20-30 minutes max. Little did I know I wouldn’t be able to put it down.

So crazy good. Read it.

Some aspects of the book, I liked very much--the relationships and banter of the detectives was great--but the killer's diary and description of the torture of victims was unpleasant to read. I personally don't enjoy books that take the reader inside the killer's mind but this book will appeal to a lot of readers who aren't as sensitive.

It is a book I could recommend to fans of serial killer fiction.

And I'll most likely read the second book in the series myself.

I really, really loved this book! The only downside to reading a book prior to publication is the very long wait until a sequel or the next book being released. Thankfully I can usually find previously written books by the authors I discover. This is a must read!