Stephen King’s The Dark Tower is already on the way for its February theatrical debut, but the people behind the film are also working on a companion TV series. Entertainment Weekly reports that, for King’s 69th birthday, production company MRC and Sony Pictures have revealed that they’re developing a spinoff series that will flesh out the film’s mythology. A prequel, the show will explore the backstory of the gunslinger Roland Deschain, played by Idris Elba — Elba is even due to appear on the show in some capacity.

The TV series will follow a young Gunslinger

Sony and MRC are working on a full 10-13 episode run, with plans to start shooting next year. The story will be based in part on the first book in the Dark Tower saga, The Gunslinger, while incorporating elements from the fourth book, Wizard and Glass. Together, the stories will chronicle Roland Deschain’s formative encounters with the demonic sorcerer known as the Man in Black while also setting him on the path of tragedy and loss that the movie will go on to resolve. Matthew McConaughey is set to play the character, but it’s not certain yet if he’ll appear on the show.

"In the movie, Roland is suffering tremendous loss. The most concrete, personal, existential heartbreak a character can have," The Dark Tower producer and co-screenwriter Akiva Goldsman told EW. "If the movie chronicles his final reach toward hope again, the TV show is the loss of that hope."

Sony and MRC are aiming to have the series premiere in 2018, around when the film will be made available on cable and streaming platforms. The companies will just need to find a distributor that isn’t troubled by the series dark themes.