“Game of Thrones”
Daenerys’ (Emilia Clarke) dragons are bigger than ever in Season 7 of “Game of Thrones.” HBO

Though “Game of Thrones” will end with Season 8 in 2018, HBO has no intention of abandoning Westeros. A spin-off series has been part of the plan for years, though actual development on a series didn’t begin in earnest until recently, at least according to HBO CEO Richard Plepler, who described the development process as running concurrent with production on the final two seasons of “Game of Thrones.” Whatever shape the eventual spin-off series takes, “Game of Thrones” showrunners David Benioff and D.B. Weiss won’t be involved, telling a SXSW audience “it’s always good to get new blood in.” On Thursday we finally learned what “new blood” means, as The New York Times revealed four screenwriters who will be developing different series possibilities set in Westeros.

The four screenwriters tapped to determine the future of Westeros on HBO are Max Borenstein, Jane Goldman, Brian Helgeland and Carly Wray. According to the Times, each are “plumbing Mr. Martin’s book for scripts.” And while the specifics are a little vague, it sounds like each writer will search out and present their own vision for a “Game of Thrones” prequel set in Westeros.

It’s an eclectic crew of writers HBO has assembled. Borenstein has carved out a niche for himself in the giant monster genre, writing the scripts for both 2014’s American “Godzilla” and this year’s “Kong: Skull Island.” Goldman wrote both entries in the over-the-top “Kingsman” spy series, plus “X-Men: First Class” and “Miss Peregrine’s Home for Peculiar Children,” demonstrating a strength for both establishing franchises and adapting existing ones. Helgeland is the old warhorse of the group, with movies like 1997’s “L.A. Confidential,” “Payback,” “A Knight’s Tale,” “Mystic River” and “Man on Fire” to his name. Finally, there’s Wray, who has written for prestige television shows, including “The Leftovers” and “Mad Men.”

HBO announced that the new scripts will “explore different time periods of George R.R. Martin’s vast and rich universe.” Since Martin has only looked back, not forward, in “A Song of Ice and Fire” affiliated books like the “Tales of Dunk and Egg” novella series (starring Daenerys Targaryen’s great-grandfather), any spin-off is likely to be a prequel series set in Westeros decades or centuries before the events of “Game of Thrones.”

If there’s any book likely to play an outsized role in the development process, it’s “The World of Ice & Fire,” an immense history and reference book Martin wrote in collaboration with Westeros.org founders Linda Antonsson and Elio Garcia. The book elaborates on pivotal moments in the history of Westeros, such as Aegon Targaryen’s original conquest of Westeros and Robert Baratheon’s rebellion against House Targaryen, the consequences of which set the stage for “A Song of Ice and Fire” and the events of “Game of Thrones.”

Martin, a veteran TV screenwriter himself, is currently collaborating on both Goldman and Wray’s scripts. Assuming HBO settles on one or more of the contracted scripts, a “Game of Thrones” spin-off could premiere as early as 2019.