Game of Thrones show-runners Dan Weiss and David Benioff have been pretty forthright in the past when it comes to the original pilot for their smash-hit HBO show. The consensus? It was not good. The full video has never been released to the public, though vestigial clues—like Theon’s and Tyrion’s mysterious blonde hair—remain in the episode that made it to air. After massive re-shoots, re-castings, and essentially constructing a new episode out of the ashes, Weiss and Benioff managed to score a hit. We may never get to see the full, original pilot, but in a new interview we have a better sense of why it was so awful.

John August (Go, Big Fish, and several other Tim Burton projects) and Craig Mazin (The Hangover sequels and Identity Thief) are screenwriters and, in Mazin’s case, personal friends of Weiss and Benioff. The pair also host a podcast called Scriptnotes, which this week had the Game of Thrones show-runners on to talk about the pilot. Mazin actually saw the original pilot directed by Tom McCarthy of Spotlight, The Station Agent, and The Visitor fame and, along with a few friends, was asked to offer his opinion.

“Watching them watch that original pilot was one of the most painful experiences of my life,” Weiss said on the podcast. “As soon as it finished, Craig [Mazin] said, ‘You guys have a massive problem.’” Was it the flashback to Ned’s brother dying that was the issue? Jennifer Ehle’s original performance as Catelyn Stark? The “lunatic,” overwrought death of Jon Arryn? Or maybe it was the fact that, according to Benioff, “none of (our friends) realized that Jaime and Cersei were brother and sister, which is a major, major plot point that we had somehow failed to establish.”

Actually it was all of that. “I was taking notes,” Benioff says, “and I had this yellow legal pad, and I just remembered writing in all caps, ‘MASSIVE PROBLEM,’ and it’s all I could think about the rest of the night. Craig didn’t really have any great ideas except that he said ‘change everything.’”

Change everything they did. Though some original footage remains—for example, you never see Sansa and Catelyn in the same frame because they just inserted Michelle Fairley’s footage to cover Ehle’s old performance—Weiss and Benioff re-shot about 90 percent of the pilot. Tom McCarthy didn’t even wind up with his name on the final product. That credit went to Timothy Van Patten, who also directed the second episode. McCarthy has said:

I turned in an early cut, and they had to recast, and I think they rethought. . . . You know, they’re taking on this huge book, and they rethought how to get into it and how to set it up. They had to change some locations, and they did quite a bit of work on it since I left. I’d like to think I had some impact on it, but I don’t think much of that is mine anymore.

Though he doesn’t seem put out about the big changes, McCarthy said the experience was enough to turn him off TV directing. Calling it a “writer’s” or “studio’s” medium rather than a “director’s,” he said he wasn’t in a hurry to “rush back to” TV directing. In fact, the 2016 Oscar nominee, who clearly has rebounded quite well from the experience, hasn’t been back since.

Mazin calls the changes Weiss, Benioff, and director Timothy Van Patten were able to work a miracle:

I will never forget being invited to the premiere of the first season. I went in just thinking (skeptically), “Well, I guess we’ll just see how this goes.” I sat there and this show unfolds and I am stunned. Stunned. And I very specifically remember walking out and I said to [Weiss and Benioff], “That is the biggest rescue in Hollywood history.” Because it wasn’t just that they had saved something bad and turned it really good. You had saved a complete piece of sh*t and turned it into something brilliant. That never happens!

The existing pilot is a pretty solid example of how to introduce a vast and complicated universe elegantly and with humor and drama. Little scenes that both build character and deliver exposition—like the short one where Catelyn Stark and Maester Luwin talk about getting Winterfell ready for their guests—help put flesh on the bones of an already intriguing story.

Weiss and Benioff went on to discuss their own working dynamic, which anyone who has watched the behind-the-scenes videos know is a relationship that has to span several countries—Spain, Ireland, Iceland, Croatia, Morocco—when the show is in production. So how do they make it work? “I think in the 20-something years that I have known Dan,” Benioff says, “I think he’s threatened to kill me while drunk at least three times. And not in a joke-y way, but like, ‘I will beat your skull in.’ And the next day I always tell him, ‘Dude, you threatened to kill me last night,’ and he never remembers.”

But it’s not just booze and death threats that keep these two together. “Dan has this tactic, where he will write a 14-page e-mail and he knows that after four or five pages, I will get so bored that I give up,” Benioff said, “so he always wins the arguments.” Oh that’s how to get David Benioff to do what you want? Write a really long e-mail? Well get cracking on those “we demand to see the original, terrible pilot” letters, folks. Think wordy, George R.R. Martin thoughts and we might get that footage in no time.