When Benioff and Weiss were looking for directors for “Thrones” Season 7, McElhenney pitched them on hiring his frequent “It’s Always Sunny” director Matt Shakman. Benioff and Weiss accepted and Shakman was hired to direct two Season 7 episodes, including the battle-heavy intalllment “The Spoils of War.” The director proved to be a great addition to the “Thrones” creative team, but Weiss and Benioff decided to mess with McElhenney by telling him otherwise.

“We thought it would be funny if we told Rob that it was not working out with Matt and that he was a total disaster,” Weiss said. “He would feel so guilty because he recommended him. We went back and forth [on email] slowly, not throwing it out there all at once, asking questions like, ‘So when Matt’s on set, how does he usually behave?’ Rob was all, ‘What‐what‐what’s wrong?!’ We told him we’re going to have to step in and take over the episode because it’s turned into such a mess.” Shakman said McElhenney was left “tortured” by the prank, adding “That was the darkest practical joke…He was so concerned for me and was like, ‘What can I do? Who can I talk to?’ It went on for way too long.” The Season 7 prank would come back to haunt Weiss and Benioff in a way in Season 8, where a Starbucks coffee cup notoriously ended up in a finished scene. Benioff and Weiss reveal in the book they originally thought they were being pranked when word first hit that a coffee cup was left in an episode that aired on HBO. “I couldn’t believe it,” Benioff said. “When we got the email about it the next day, I honestly thought someone was pranking us, because there had been things before where people were like, ‘Oh, look at that plane in the background!’ and somebody had Photoshopped it in. I thought, ‘There’s no way there’s a coffee cup in there.’ Then when I saw it on the TV I was like, ‘How did I not see that?’” “Fire Cannot Kill a Dragon: Game of Thrones and the Untold Story of the Epic Series” will be available to purchase starting October 6. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.