A fifth writer, and show pitch, was added after the initial announcement
Bryan Cogman, the writer behind many first-run Thrones episodes, has stepped up to develop a fifth idea, reports Entertainment Weekly.
Martin is heavily involved with the world-building
"I've actually been working with all four [now five] of the writers," Martin wrote. "Every one of the four has visited me here in Santa Fe, some of them more than once, and we've spent days together discussing their ideas, the history of Westeros and the world beyond, and sundry details found only in The World of Ice & Fire and The Lands of Ice & Fire... when we weren't drinking margaritas and eating chile rellenos and visiting Meow Wolf. They are all amazing talents, and I am excited to be working with them. In between visits, I've been in touch with them by phone, text, and email, and I expect there will be a lot more back-and-forth as we move forward."