EXCLUSIVE: Sylvester Stallone‘s Balboa Productions is teaming with Channing Powell (Tales of the Walking Dead) to develop a series adaptation of the 4MK books by J.D. Barker.

Set in Chicago, Barker’s novels follow Detective Sam Porter as he hunts the elusive Four Monkey Killer, a murderer who has terrorized the city for years with a chilling and highly personal code of judgment. Guided by the maxim “hear no evil, see no evil, speak no evil,” the killer removes the ears, eyes and tongues of his victims, turning every crime scene into a ritualized message. But the true horror lies in the unspoken fourth commandment, “do no evil,” which reveals the killer’s deeper agenda: exposing hidden corruption by punishing the guilty through the people they love most.

The adaptation will draw from Barker’s original 4MK trilogy The Fourth Monkey, The Fifth to Die and The Sixth Wicked Child, as well as a recently announced prequel trilogy, whose first installment, The First Scarlet Door, is slated for worldwide release September 22.

Powell will showrun, write, and executive produce alongside Stallone and D. Matt Geller. Christian Bersani will oversee the project for Balboa Productions, after bringing the material to Powell.

In a statement on the 4MK series, Stallone said, “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.”

Powell told us, “What drew me to 4MK 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.”

Barker said: “From the start, 4MK was designed to be a relentless, psychologically charged ride, one where every revelation cuts deeper, every secret carries a cost, and every character is forced to confront the darkest parts of themselves. Sylvester Stallone and the team at Balboa immediately saw the power, danger, and franchise potential in that world, and Channing brings exactly the kind of instinct for character, tension, and longform storytelling that can make it land with real force on screen. With this creative force, 4MK won’t just be gripping television, it will be the kind of series that gets under people’s skin and stays there. I couldn’t be more excited to see it come to life.”

Powell currently serves as co-executive producer on MGM+’s sci-fi horror series From, starring Harold Perrineau. She previously served as showrunner and executive producer on AMC’s Tales of the Walking Dead, which she co-created with Scott M. Gimple, and worked across multiple seasons of The Walking Dead. Prior to that, she created and exec produced the international co-production The Feed for Prime Video and Sky, and began her television career writing on USA’s White Collar.

Barker is a bestselling author of contemporary thriller fiction whose work has reached readers in more than 150 countries across two dozen languages and been optioned for both film and television. A regular collaborator with James Patterson, he co-authored the gothic thriller Dracul with Bram Stoker’s great-grandnephew, Dacre Stoker, selling film rights to Paramount with Andy Muschietti attached to direct.

Balboa recently wrapped production on Season 4 of Stallone’s hit Taylor Sheridan series Tulsa King, as well as Amazon MGM’s untitled Mike Thornton feature starring Reacher breakout Alan Ritchson. The company is also developing Blood Aces, which will see Stallone and Yellowstone star Cole Hauser team to produce, with Hauser attached to star as shady casino operator Benny Binion.

Stallone and Balboa Productions are represented by IAG and Kleinberg, Lange, Cuddy & Carlo. Powell is repped by UTA, TFC Management and Johnson Shapiro Slewett & Kole. Barker is repped by Joel Gotler of Intellectual Property Group and attorney Wayne Alexander.