George R.R. Martin is developing a new series at HBO

Despite the ever-present demands of fans to finish writing A Song of Ice and Fire, George R.R. Martin remains a man with many irons in the fire, including a newly revealed series in development with HBO. This new series will be a science fiction project based on Roadmarks by Roger Zelazny, who Martin considered a friend and a mentor.

While rumors have swirled about Martin potentially working on a non-Game of Thrones series for HBO recently, he put an end to the speculation on Thursday with an official post on his Not a Blog website. In the post, Martin explains that his Roadmarks series is in development, but only development, and the reason he hadn’t announced anything before now is because development in television is always an uncertain process.

In the development process, Martin is working with writer Kalinda Vazquez on the pilot. Vazquez worked on developing a show with Martin several years ago based on his werewolf novella, which didn’t get picked up, but since then has written for shows like Star Trek: Discovery and Fear the Walking Dead. Martin says the he’ll only serve the series as an executive producer and that Kalinda will work as the showrunner if the series gets ordered by HBO.

Roadmarks’ plot revolves around a central highway that links all time and possible realities. Each of the highway’s many exits lead to a new future or past from one reality or another. It’s a complex premise, and the book makes use of it by throwing the protagonist Red Dorakeen, who uses the highway to venture all through the history, into various worlds. While Roadmarks was originally planned as a series, Zelazny only ever wrote the first book, but Martin says that he sees plenty of potential to expand on the story should the HBO show get picked up.

While any new project from Martin certainly has the potential to turn into something huge, for now Roadmarks is only in development and still doesn’t have a pilot ordered. According to Martin, if the show does go to series, fans shouldn’t expect to see it for a least a year or two.