Earlier this month, HBO revealed that they’d begun developing four separate Game of Thrones spin-offs. The plan is to find at least one show (and possibly more) to take the place of the smash fantasy drama when it concludes after 2018’s eighth and final season. Now, creator George R.R. Martin has revealed that the network will have yet another script to choose from, as a fifth series is now in the works.

“We had four scripts in development when I arrived in LA last week, but by the time I left we had five,” Martin wrote on his blog. “We have added a fifth writer to the original four. No, I will not reveal the name here. HBO announced the names of the first four, and will no doubt announce the fifth as well, once his deal has closed. He’s a really terrific addition, however, a great guy and a fine writer, and aside from me and maybe Elio [Garcia] and Linda [Antonsson], I don’t know anyone who knows and loves Westeros as well as he does.”

The unnamed writer joins the ranks of Jane Goldman (X-Men: First Class), Carly Wray (Mad Men), Max Borensetein (Kong: Skull Island), and Brian Helgeland (A Knight’s Tale), all of whom are working on their own GoT series. Martin also clarified that he has indeed been working with all four of the originally announced writers instead of just two as was originally reported. He also said he had pitched one of the four stories before the other creatives were brought on, along with a second story that did not enter development.

(Read: Top 25 TV Shows of 2016)

Martin went on to say he wasn’t a fan of calling the series “spinoffs,” preferring to call them “successor shows.” He also revealed each of the shows is set up as a prequel, though they might not follow certain stories for which fans are hoping.

“We’re not doing Dunk & Egg,” he said, referring to the series of novellas about Ser Duncan the Tall and his squire, Egg, the future King Aegon V Targaryen. “Eventually, sure, I’d love that, and so would many of you. But I’ve only written and published three novellas to date, and there are at least seven or eight or ten more I want to write.” Hoping to avoid the show outpacing the books, as happened with GoT, Martin said he’d rather wait to finish Tales of Dunk and Egg before taking it to TV.

He also said none of the new shows are focused on Robert’s Rebellion, the war that took place 17 years prior to Game of Thrones. He assured fans everything they’d want to know about the event will be revealed by the time he finishes A Song of Ice & Fire, however. “There would be no surprises or revelations left in such a show, just the acting out of conflicts whose resolutions you already know. That’s not a story I want to tell just now; it would feel too much like a twice-told tale.”

Finally, Martin reiterated that just because HBO has ordered development on the five shows, it doesn’t mean all of them will get made. Some may make it to pilot, some to series, and some may even become miniseries. It’s likely a few of them won’t be made at all, but odds are fans will get to see the early days of Westeros in one form or another after GoT ends.

Season seven of Game of Thrones premieres on July 16th. Watch a teaser for the new season below.