Fresh details have come to light about the fifth Game of Thrones spinoff, which was previously discussed, but not in any length. According to Entertainment Weekly, Game of Thrones co-executive producer Bryan Cogman is writing the fifth project alongside George R.R. Martin.

Writing on his Tumblr, Martin said that, like the other four spinoffs, Cogman’s is going to be a prequel as opposed to a sequel. Cogman’s show will adapt some part of the Game of Thrones universe, Martin said, though he offered no further details.

“I can say that, like the other pilots, it will be a prequel rather than sequel, a successor rather than a spinoff,” Martin said. “Bryan’s series will be an adaptation, and one that will thrill most fans of the books, I think, set during a very exciting period of Westerosi history. And I’ll be working with him every step of the way; we’re going to be co-creating the show.”

Martin also clarified in his Tumblr post that, as has been said before, there is a very small chance that all five shows get made. It’s more likely that two or three advance to the pilot stage, with maybe one getting the green light. “Much as I might love the idea, HBO is not about to become the GAME OF THRONES network… but we could possibly see two or even three make it to the pilot stage, with one series emerging on air in 2019 or 2020,” he said. “And the others maybe later, if they come out as well as we all hope. Then again, maybe… but I should not speculate, you folks get WAY too excited. Truth is, no one knows. Least of all me.”

The seventh season of Game of Thrones wrapped up recently, and the season finale had some epic moments. The eighth and final season is reportedly due to begin production in October ahead of its release in 2018 or 2019.

Explaining why HBO is working on so many Game of Thrones prequels, programming president Casey Bloys said it would be “insane” to not at least think about successor shows.

“It would be insane–with a universe like [author Georg R.R. Martin] has created that is so vast and has so many characters and so many timelines–to not, at least, entertain the idea, which is what we’re doing,” he said.

“So the idea was, if we’re going to try it, let’s take a couple of shots and see,” he said. “My hope is at least one lives up to the level of quality [showrunners David Benioff and D.B. Weiss] have set,” Bloys explained.

Are you looking forward to the Game of Thrones spinoffs? Let us know in the comments below!