It wasn't a simple task for George R.R. Martin to trust showrunners David Benioff and D.B Weiss with his masterwork, "Game of Thrones."

Benioff recalls the day they called the writer, and tried to get him on board.

"We thought this was going to be a very tough sell, because we said, 'We love your books. We would love to adapt them. We don't think they can be movies,' " Benioff said. " 'We think maybe it can be an HBO series.' And we're waiting to hear the click, because, you know, there's just less money and for a novelist, it's less money in letting your book get optioned by HBO versus a movie studio."

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