I have read a few of Rob Sinclair's books which I have thoroughly enjoyed but this is only the second in this series that I have read however, I think it works well as a standalone.

Told from a dual timeline and set in various countries, this is a great story that has fantastic characters, an excellent plot, loads of action, suspense and thrills and all written at a great, fast pace, this is a really good action/adventure/spy/thriller so will appeal to many. There are violent scenes but only what you would expect for this type of book and nothing that is over the top ... well I didn't think so.

Excellent book that I thoroughly enjoyed and many thanks to the author, Boldwood Books and NetGalley for enabling me to read and share my thoughts of this, the latest in the James Ryker series.

Another brilliant fast paced James Ryker read by Rob Sinclair. I found it hard to put down once I started.

This is high-stakes thriller that grips you from the very first page and doesn’t let go. Packed with adrenaline-fueled action, suspense, and surprising emotional depth, The Enemy Within is another electrifying entry in the James Ryker series.

Former intelligence operative James Ryker, the protagonist, thought he had left his past behind—until two strangers track him down with an urgent plea; Find Gregor, a fugitive on the run from Russian authorities. But this isn’t just another mission. Gregor was once a terrified six-year-old Ryker met in Ukraine, the son of a ruthless arms dealer Ryker had no choice but to abandon. Now, after escaping a Siberian gulag, Gregor is out for revenge, and Ryker is dragged into a deadly game where deception is everywhere and trust is a dangerous luxury.

Rob’s storytelling is masterful, striking a perfect balance between relentless action and rich character development. Ryker remains a fascinating protagonist—hardened by experience yet haunted by his past. The dual timelines weave together seamlessly, offering longtime fans a deeper look into Ryker’s past while making the story fully accessible to new readers.

From the sun-soaked streets of France to the icy battlegrounds of Russia and Ukraine, The Enemy Within hurtles forward at breakneck speed. Rob also injects real-world geopolitics into the plot, making every twist feel urgent and authentic. The action is intense, the stakes are sky-high, and Ryker’s personal journey adds a surprising emotional punch to the thrills.

Though this is the 13th book in the James Ryker series, it stands firmly on its own, delivering a gripping, high-octane experience for both loyal fans and newcomers. If you love smart, fast-paced espionage thrillers with complex characters and heart-pounding suspense, this one is a must-read.

Readers with a Reacher-shaped hole in their lives will not want to miss Rob Sinclair’s latest thriller featuring former intelligence agent James Ryker, The Enemy Within.

With his profession having tested him like nothing else, James Ryker is a man who has plenty of scars that refuse to heal. Having witnessed sights that would have felled a weaker individual, Ryker is still haunted by a six-year-old boy in desperate need of protection that he had no choice but to walk away from. As the son of one of Ukraine’s most dangerous and politically influential arms dealers, Gregor had not been part of Ryker’s mission. However, leaving him behind has always weighed heavily upon his shoulders…

Two decades later, Ryker is approached by two strangers in the Antibes asking for help to find Gregor. Having committed major offenses against the Russian state, Gregor has escaped from a gulag in Siberia. With old demons and painful memories from the past forcing Ryker to confront his previous actions head on, he must find Gregor and get the answers she seeks.

But with enemies at every turn, Ryker needs to watch his step – because what he’s after might have been hiding in plain sight all along.

Bold, daring, gritty and gutsy, The Enemy Within is a hair-raising rollercoaster ride that doesn’t let up for a single second. Rob Sinclair sure knows how to write an electrifying, panoramic and engrossing yarn and The Enemy Within is a propulsive adventure that is a struggle to put down.

Rob Sinclair’s The Enemy Within marks the thirteenth installment in the high-octane James Ryker series, proving once again that espionage thrillers can be both action-packed and deeply introspective. With a gripping dual-timeline narrative spanning twenty years, Sinclair masterfully weaves together past and present, delivering a story filled with political intrigue, betrayal, and raw emotion.

James Ryker, a former intelligence operative, is drawn back into a world he thought he had left behind when two strangers approach him in Antibes, France. Their request? Locate Gregor Rebrov, a fugitive on the run from Russian authorities. But Gregor is no stranger to Ryker. Decades ago, Ryker knew him as Gregor Minko, a terrified six-year-old boy caught in the crosshairs of his father’s dangerous dealings. Now, Gregor has escaped from a Siberian gulag and is determined to settle old scores. Ryker, driven by guilt and a sense of unfinished business, embarks on a dangerous mission that takes him deep into the heart of the Ukraine-Russia conflict, where loyalties are tested and nothing is as it seems.

Sinclair’s storytelling is razor-sharp, balancing explosive action sequences with well-developed characters. Ryker remains a fascinating protagonist—hardened by years of experience but burdened by the weight of his past decisions. The alternating timelines offer a compelling look at how his past missions shaped him, adding layers to his character that longtime fans will appreciate while keeping the novel accessible to new readers.

The Enemy Within is relentless in its pacing, pulling readers through a maze of deception, shifting alliances, and pulse-pounding confrontations. The action is intense, the stakes are high, and the emotional weight of Ryker’s journey adds a poignant depth to the narrative. Sinclair does a fantastic job integrating real-world geopolitics into the story, making it feel all the more urgent and relevant.

While The Enemy Within is part of a long-running series, it works well as a standalone, offering enough context for newcomers without slowing the story down. Fans of espionage thrillers, from Robert Ludlum to Mark Greaney, will find themselves hooked from the very first page. With a gripping plot, a morally complex protagonist, and a powerful conclusion, this is a must-read for thriller enthusiasts.

Many thanks to Boldwood Books and NetGalley for providing an advance copy in exchange for an honest review.

⭐️⭐️⭐️⭐️⭐️ – A gripping and intense espionage thriller that keeps you on edge until the very last page!

The Enemy Within by Rob Sinclair is the 13th book in the excellent James Ryker series and I have loved reading this fast-paced, action-packed thriller especially as they are full of action, twists and turns throughout and every book has been a joy to read. This book travels back and to the present time, you travel to France to Russia and Ukraine, which made it an interesting read. The main character James Ryker is excellent.

I highly recommend this series especially if you love a good whodunnit.

Big Thank you to NetGalley and Boldwood Books for my ARC.

James Ryker is an agent currently in Antibes. With the use of flashbacks and present day we follow Ryker as he searches for Gregor, the son of a Ukrainian mobster from 20 years ago. I found it difficult to get into the story until the time Gregor is found when the story ramps up and becomes unputdownable. It took about half of the book to get a feeling for the characters as the story whipped back and forth. The ending was more exciting than the scene setting stages. I would still recommend the book as once the story settled down it became addictive. With thanks to the author, Netgalley and Boldwood books.

For anyone that enjoys a spy thriller, this is one to pick up.

The novel is set in both the past and the present, in Russia and Cyprus, keeping the reader on their toes, but helping to set the scene as to why Ryker has been tasked with finding someone he hasn't seen in many years. However, you will have to wait until further into the story to find out what truly happened all those years ago and whether Ryker regrets anything.

The twists that appear as the story unfolds will mean that even if you think you can predict the outcome, you will come up short.

Rob Sinclair's "The Enemy Within" is number 13 in a series of novels featuring ex intelligence officer James Ryker.
In this latest edition Ryker confronst his own past working undercover with one of Ukraine’s most dangerous arms dealers. The novel spans 20 years and is told in 2 timelines with several POV characters.

James Ryker/Carl Logan is a well-developed protagonist with an interesting backstory. His internal struggles and moral dilemmas add depth to the character, making him relatable and compelling.

Sinclair's portrayal of the world of espionage is both detailed and believable.

At times, the pacing of the book feels uneven, certain parts of the book drag on, causing the narrative to lose momentum.

I have only read 1 James Ryker novel in the past (#12) and would suggest that this works well as a stand-alone. "The Enemy Within" is an enjoyable thriller that offers an exciting ride through the world of espionage.
Many thanks to the author, publisher and NetGalley UK for the ARC.
3.5 stars rounded up

Book #13 in the James Ryker series. Ryker has few regrets of the events his past actions have caused. One he never forgets is having to walk away from a 6 yera old child who needed protection. Now this child is a grown man who is in desperate need of help. Ryker will do what he does best, find him and stop anyone or anything in the way. A great thriller that continues the excellent stories I've come to expect from Rob Sinclair.

We are back with James Ryker…. for his 13th adventure! 13 is unlucky for some but not Rob Sinclair!

The Enemy Within jumps from past to present and allows the reader the chance to get to know Gregor Rebrov.

Gregor hasn’t had a great upbringing, and he’s again got himself in trouble.

Ryker is approached one day and informed of Gregor’s plight…Ryker has history with Gregor and his parents from a past mission so sets out to find him.

Of course it’s not going to be as simple as that in Ryker’s world. Firstly who were these two who informed Ryker.. and how do they know so much about him? Something doesn’t smell right.

Looking at the past we learn not only of the fate of Gregor and his family but also Ryker himself. We see how the job has changed him and also a little bit more about Ryker’s history with those who pull his strings, Mackie and Winter.

Back in the present we now understand why Ryker wants to help Gregor.. he owes him.. owes his mother.. Ryker isn’t the same man he was.. still as deadly but the toll of the job has really changed him. Is this Ryker’s chance at a little redemption?

What Rob Sinclair has done wonderfully is weave a fresh story for Ryker but at the same time added character development.. you’d think by now we would know what makes Ryker tick, but he never ceases to amaze me. Ryker has his flaws, but it’s these flaws that have made him the man he is.

Events have also changed Gregor and Ryker has to try and figure out if any of the boy he knew still remains.. it’s as he gets to know him that we finally understand Gregor’s own motivations.. the devastation that has brought him to where they are now..it’s a horrific and brutal punch that even rocks Ryker.

The setting was very poignant too as the author explores the war between Ukraine and Russia, it just makes those poignant moments all the more real.

The Enemy Within is packed full of action, political intrigue, betrayal and blood with a healthy dose of character development. For me it was all about the motivations…the depth and emotion.. Simply wow!

Thrilling thriller. Plenty of guns, weapons, secrets, spies, twists of fate and the like to keep the heart racing in this one. Once again, all with James Ryker in the thick of it.
I like that the setting is in Eastern Europe involving none other place than the Ukraine, Donbas, and Russia. Despite this being a work of fiction, the author seems to explain some of the given unrest in the area, which appeas to hinge on the history of these areas and their intermittent grips and grasps at each others' throats. Some of the storys' characters, namely Roman Mintos and his men, were striving for automony of Donbas in a patriotic endeavor to achieve his goal.

The story's timeframe triggers from about 2014 to 2022. The two-pronged timeframes made it confusing and distracting for me as I read. However, it eventually smoothened out and came together for me.

~ Eunice C., Reviewer/Blogger ~

February 2025

Disclaimer: This is my honest opinion based on the complimentary review copy sent by Net Galley and the publisher.

The Enemy Within by Rob Sinclair is a fast-paced, action-packed thriller that kept me hooked from start to finish. I really enjoyed the dual timeline, switching between past and present, which added depth to the story. James Ryker is a great main character—flawed but compelling—and his journey is full of twists and intense moments.
The settings, from France to Russia and Ukraine, made the story even more gripping. There’s plenty of action, political intrigue, and unexpected betrayals, which kept me guessing the whole time. I did get a little lost with the time jumps at times, but that didn’t take away from the excitement. The tension builds perfectly, leading to a twisty and satisfying ending.
Overall, this was a thrilling read that had me turning pages as fast as possible. If you love spy thrillers with strong characters and nonstop action, this one is definitely worth reading!
Very grateful to the publisher for my copy through NetGalley, opinions are my own

Overall 4.5*
Yet another good addition to this series about Ryker, who is mellowing in old age...Not!! Set in and around Ukraine this time with a dual timeline of today and 20 years ago, it is very well paced and a great page turner. Lots of killings and violence but that is to be expected from this kind of novel and only adds to the authenticity of it. Loved reading the political points of view and the only reason it lost half a star was that I did lose the time frames from time to time however that may just have been me.

Thanks to Netgalley for the ARC to review

Ex-intelligence agent James Ryker has done many things in the past he'd prefer to forget. The last time he he saw Gregor Minto - son of Ukraine's most dangerous and politically influential arms dealers - Gregor was a scared six-year-old boy in need of protection. But Ryker had to walk away. The boy wasn't the mission. Twenty years on and Ryker is approached by two strangers in Antibes, France, asking for his help in finding Gregor - now going by the name og Gregor Rebov. With a back catalogue of "crimes against the Russian state," Gregor has escaped from a gulag in Siberia and is now in the wind.

This story is told in the past, Twenty years ago, and the present day. The pace is fast, the characters are well-developed, and the story has been well-written. In this action-packed story, I didn't know who I could trust. There were lots of twists in this gripping read.

Published 15th February 2025

I would like to thank #NetGalley #BoldwoodBooks and the author #RobSinclair for my ARC of #TheEnemyWithin in exchange for an honest review.

The Enemy Within
by Rob Sinclair
Release date: Feb 15, 2025

An electrifying thriller where the past never stays buried.

Some books grip you from the first page and refuse to let go—The Enemy Within is one of them. Rob Sinclair delivers a high-octane espionage thriller filled with danger, deception, and a relentless chase across the globe. Fans of tightly woven plots and morally complex heroes will find themselves completely immersed in James Ryker’s world, where trust is scarce and old ghosts refuse to stay buried.

James Ryker, a former intelligence agent with a past he’d rather forget, is thrust back into action when two mysterious figures track him down in Antibes, France. Their request? Find Gregor Rebrov, a fugitive with a history of defying the Russian state. But Ryker knows Gregor by a different name—Gregor Minko, the scared six-year-old boy he once had to abandon for the sake of a mission. The weight of that decision still lingers, and now, two decades later, Ryker is forced to confront the consequences.

What follows is a relentless, pulse-pounding journey that takes Ryker across dangerous landscapes and into the crosshairs of powerful enemies. As he pieces together Gregor’s tangled past, Ryker finds himself questioning everything—his choices, his loyalties, and whether he himself might be to blame for the chaos unfolding around him. The deeper he digs, the more sinister the truth becomes, leading him right back to a place he never expected: home.

Sinclair’s writing is razor-sharp, balancing intricate spy craft with raw, emotional depth. Ryker is a protagonist who feels real—hardened by experience yet haunted by regret. The tension is unrelenting, with each revelation hitting like a well-placed punch, keeping the reader constantly on edge. The novel’s pacing is masterfully executed, with short, gripping chapters that make it nearly impossible to stop reading.

For fans of espionage thrillers with a human touch, The Enemy Within delivers everything you could want—action, intrigue, and a deeply personal story of redemption. Sinclair doesn’t just tell a spy story; he makes you feel the weight of every decision, every loss, and every betrayal. If you’re looking for a gripping read that will keep you hooked until the very last page, this one is a must.

Thank you to Boldwood Books for providing this advance copy via NetGalley for my honest, voluntary review.

#TheEnemyWithin #NetGalley

Thank you to @rachelsrandomresources for my copy of this book in exchange for an honest review.

I do love a good Reacher type hero in a book and James Ryker is just that. This book sees him in Russia looking for an old friend, and flashbacks to Cyprus when he worked for the friend’s family. There’s so much going on in this one, and it’s all action. Things get even more interesting once Ryker gets to Russia and Ukraine, and he even admits he was wrong at one point!

I believe this is number 13 in the Ryker series but can just as easily be read as a standalone. There’s enough background given in each book about James and Winter, his “boss”, that makes this a really good series that you can dip in and out of. I’ve read one of the previous books, number 12, and this one isn’t a direct follow-on from that.

A really good action-packed movie of a novel, draws you in at the start and doesn’t let you out till the end. Just the way a good book should be.

The Enemy Within by Rob Sinclair
James Ryker #13

Once again, I wish that I had not read an advanced readers’ copy of a book so far into an ongoing series without having read previous books in the series because though it flowed and the story was easy enough to follow, I was not invested in the main character or the theme of the story. It could also be that living where I do in Lebanon with a tentative ceasefire and new government in place this story was a bit too close to home…though distant geographically.

The story was well written, concise, well plotted, and characters well developed. There was plenty of action and enough backstory to keep things moving. Ryker, the main character, is supposedly reformed…somewhat…and there are plenty of evil characters to dislike and wish bad luck. I am guessing that those who HAVE read the previous books will slot in smoothly with this book’s theme and root for Ryker eagerly waiting to see what he will get up to next. I will let them and move on to the next book in my queue and wish all James Ryker fans happy reading.

Can this book stand alone without reading previous books in the series? Yes
Would I have enjoyed it more if I’d read the previous books in the series? I think so
Will I read more books in this series? Probably not

Thank you to NetGalley and Boldwood Books for the ARC – This is my honest review.

3-4 Stars

Another killer read by a very talented author. Book was well written, and doesn't disappoint! Recommended for anyone who loves a good whodunnit.

The Enemy Within is the latest novel in the James Ryker series. I've not read all the books, but I've read enough to know they guarantee an action-packed adventure in which our main character will encounter a few baddies.

The Enemy Within quickly grabbed my attention, especially with the addition of Gregor's point of view from the gulag, while James is in a somewhat better position in the south of France. As we're taken back to Ryker's past, events in the present start to unfold, and we're also treated to a trip to the Ukraine and Russian border.

I don't know if this book is more violent than earlier ones in the series or because one of the storylines is Ryker as a younger man, it's just that we discover how truly lethal he used to be, but the body count is certainly high.

The ending was delightfully twisty, and readers will learn much about Ryker from reading the latest instalment.

It is a violent, bloody and twisty tale, with elements of the current difficulties of the Ukraine war threaded through, which also makes it shockingly current.