A new dark crime thriller is officially in development as Sylvester Stallone’s Balboa Productions teams with The Walking Dead veteran Channing Powell to adapt J.D. Barker’s bestselling 4MK book series for television. The project is being positioned as a psychological crime drama built around a long-running investigation into one of fiction’s most disturbing killers.
Channing Powell, best known for her work on The Walking Dead franchise and the anthology series Tales of the Walking Dead, is set to serve as showrunner, writer, and executive producer on the adaptation. The series is being produced under Stallone’s Balboa Productions banner, with Stallone executive producing alongside Powell and D. Matt Geller. In addition, Christian Bersani is overseeing the project for the company, having originally brought the idea to Powell’s attention.
Barker's 4MK serial killer novels take place in Chicago and center on Detective Sam Porter, a relentless investigator drawn into a years-long hunt for a brutal and highly organized murderer known as the Four Monkey Killer. The case quickly becomes one of the most disturbing in the city’s history, not only because of the violence involved, but because of the chilling symbolism left behind at each crime scene.
The killer operates with a ritualistic pattern based on a twisted interpretation of the proverb “hear no evil, see no evil, speak no evil.” Each murder is staged to reflect this philosophy, with victims subjected to mutilations such as the removal of ears, eyes, and tongues. As Detective Porter digs further into the case, the story expands beyond a traditional cat-and-mouse pursuit. The killer’s actions are eventually tied to a broader belief system centered around justice and corruption.
According to Deadline, the series adaptation will pull from Barker’s original 4MK trilogy. Those are the books The Fourth Monkey, The Fifth to Die, and The Sixth Wicked Child. Additionally, it will also incorporate elements from the newly announced prequel trilogy, beginning with The First Scarlet Door. While you can currently purchase the original book trilogy, The First Scarlet Door isn't set for release until Sept. 22, 2026.
That said, it might be a good idea to catch up on the 4MK book series ahead of the adaptation, as it lays the foundation for the characters, the killer’s psychology, and the overarching mythology that the series is expected to expand upon. Of course, the show is only in its early stages of development. However, it’s never too early to start getting familiar with the source material, especially since the 4MK universe is already structured as a multi-book, interconnected crime saga with plenty of material to draw from.
Below, we shared Powell and Stallone's statements about the 4MK series adaptation via Deadline:
“J.D. Barker has created a world with enormous scale, real danger, a ruthless narrative engine, and the kind of mythology that is tailor-made for premium television. Channing Powell is not only a powerhouse writer and producer, but a true creator with a rare command of dark, character-driven storytelling, and she is exactly the right force to bring 4MK to the screen. This is the kind of property that audiences don’t just watch, but get pulled into, and it has all the makings of a series that can hit hard, travel globally, and leave a real mark.” - Sylvester Stallone
"What drew me to4MK immediately was its intensity, its intelligence, and the way it keeps tightening the screws until you can barely breathe. Beneath the suspense is a story about guilt, justice, corruption, and the emotional wreckage people leave behind. J.D. Barker has created a world that is bold, dangerous, and deeply addictive, and Sylvester Stallone and the Balboa team provide the invaluable support needed to bring my adaptation to the screen, driving this series toward real scale.” - Channing Powell
Sadly, this is all that's been revealed about the upcoming series. However, more details should be announced as the project moves further into development. This includes potential casting updates, production timelines, and a clearer sense of when the series could begin filming or eventually premiere.
Stay tuned to Undead Walking for more news and coverage on upcoming projects from The Walking Dead cast and crew!
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