As the long-awaited feature film The Dark Tower is poised to open at the box office, the potential TV series is taking a big step forward.

Glen Mazzara (The Walking Dead) has been tapped to serve as showrunner on the TV adaptation of the ambitious Stephen King series. The TV take, envisioned as a straight-to-series project, is in its early stages, and tapping a showrunner is the key first step. A network is not yet attached. Sources tell The Hollywood Reporter that it is being eyed for a short-order (between 10 and 13 episodes) and a home on cable or streaming outlets by producers Media Rights Capital and Sony Pictures Television. Production is eyed to begin in 2018, though nothing is locked in given all the variables.

"I've been a Stephen King fan for decades, and the opportunity to adapt The Dark Tower as a TV series is a great honor," Mazzara tells THR. "The events of The Gunslinger, Wizard and Glass, The Wind Through the Keyhole and other tales need a long format to capture the complexity of Roland's coming of age — how he became the Gunslinger, how Walter became the Man in Black, and how their rivalry cost Roland everything and everyone he ever loved. I could not be more excited to tell this story. It feels like being given the key to a treasure chest. And oh yeah, we'll have billy-bumblers!"

The feature film, which opens Friday and is already generating mixed reviews, is considered to be independent from the TV series — though there is some overlap. Slated to appear in the series are Idris Elba, who stars as Roland Deschain (aka the Gunslinger); Dennis Haysbert (as Roland's father, Steven Deschain); and young star Tom Taylor (Jake Chambers, the son-like figure to the Gunslinger). The potential TV series will revolve around a younger Roland and his group — with those roles currently uncast. The TV entry will be based on Wizard in Glass, the fourth book in The Dark Tower series. While insiders do not see the potential TV series as a prequel, an origin story is more appropriate to describe the vision for the project.

Akiva Goldsman — who was originally slated to pen the script when the TV series was set up at Universal — is attached to exec produce alongside his Weed Road Pictures president of production Gregory Lessans. Imagine TV's Ron Howard and Brian Grazer are also on board as exec producers. Feature film director Nikolaj Arcel and co-writer Anders Thomas Jensen are not involved. Mazzara will take the lead with writing the series as well as overseeing day-to-day operations on the ambitious project.

Mazzara was The Walking Dead's second showrunner, coming in to replace Frank Darabont on the AMC zombie drama. His TV credits include A&E's Damien as well as Crash, The Shield and Life. He's repped by CAA.

The Dark Tower is in theaters Friday.