When it comes to Game of Thrones spinoffs, HBO has its ground covered: The network is developing at least five reported potential offshoots for the mega-popular fantasy epic. And one of them has just taken a giant leap closer to getting an official series order.

According to Deadline, HBO has greenlit a pilot for an untitled prequel project from GoT author/executive producer George R.R. Martin and feature writer Jane Goldman (Kick-Ass, Kingsman: The Golden Circle). It's set thousands of years in the past, during the Age of Heroes, when the Children of the Forest still lived alongside humans, when Winterfell (the Starks' home) and The Wall were built, and when the White Walkers tried to invade Westeros for the first time.

The show is described as chronicling “the world’s descent from the golden Age of Heroes into its darkest hour," teasing that it will unveil "horrifying secrets of Westeros’ history," the "true origin" of the White Walkers, and "the mysteries of the East to the Starks of legend."

"It’s not the story we think we know,” the description closes ominously. Given GoT's affinity for big, series-upending twists, that's not too hard to believe

There is, however, one notable distinction: After years of being criticized for its lack of female perspective (at least in the writer's room), a woman will finally be taking the reins. Goldman will serve as showrunner and executive-produce alongside Martin, as well as fellow GOT co-executive producer Vince Gerardis and Damages and Bloodline co-creato Daniel Zelman. As previously announced, GOT creators/executive producers David Benioff and  D. B. Weiss have no involvement in any of the potential spinoffs.

Deadline notes Goldman's role means their could be a female lead character — a departure for GoT, which is focused on Jon Snow's journey. If the prequel does get a series order, it likely won't air until at least 2020, one year after GoT's upcoming series finale.

"I want the final season of Game of Thrones to be the final season of Game Of Thrones, I don’t want to use it to launch something else," Casey Bloys, HBO's president of programming, told the outlet in January. "I want it to stand as the finale of the greatest TV show of all time. I don’t want to do anything that infringes on that.”

Game of Thrones Season 8 is slated to air next year.