Two decades ago, when the author and screenwriter George R. R. Martin began work on A Song of Ice and Fire—the best-selling fantasy series that would become the HBO hit Game of Thrones—he didn't think anyone in Hollywood would be crazy enough to adapt it._ "The reaction to many of my television scripts had been, 'George, this is great, but it would take five times our budget. You have to cut it down,' says Martin, who spent the '80s writing for TV shows like Beauty and the Beast_. "A Song of Ice and Fire was a reaction to that. I said, 'I'm going write something as big as my imagination, and not worry about budget.'."

Case in point: The Battle of the Blackwater, a six-chapter-long land-and-sea war in book two, A Clash of Kings, in which disparate fiefdoms converge on King's Landing, the capital of Martin's imaginary world. With its teeming warships and castle-wall clashes, the battle is the sort of sprawling epic that would seem to be impossible to capture on screen. But _Game of Thrones _co-creators Dan Weiss and David Benioff were determined to make it all work in 55 minutes. "Everyone knew this was the episode that was going to make or break the season," says Benioff.

The resulting episode, titled "Blackwater," with a script by Martin himself, was the year's most glorious hour of TV. But getting it right required a war-room mentality all its own. Here's the story of how Martin, Benioff, and Weiss did it. Spoilers abound, obviously, but come on: At this point, how are you _not _watching this show?

···

George R.R. Martin (author, screenwriter): Dave and Dan gave me the hardest episode of the season. I think it was their subtle revenge for creating such a difficult-to-produce show. If you did everything as it was in the book, you'd have a budget approaching one of Peter Jackson's Lord of the Rings movies. There's a sea battle, a land battle, a bridge of ships that the army pours across, a chain that Tyrion builds to keep the boats on the river, many sequences on horseback...all of this would be gigantically expensive. But my philosophy as a screenwriter has always been, "Put it in. You can always take it out later if you can't afford to do it. But if you don't put it in to begin with, then it'll never be in."

Dan Weiss (co-creator): After you get the script, you get a sense of the reality of what you're going to be able to get on-screen. There was a call a month after he gave us the script, where we said, "George, we hate to tell you this, but the chain's not going to be in it." And then we had to call and say, "George, we just don't have time for so many horses. They slow things down."

Martin: I wouldn't say I get frustrated. But it's a loss. It would be harder, if not for my previous experience in TV. I love the show, but I wish we had a couple more episodes every season.

**Weiss: **The battle specifics were constantly evolving to meet our budget. We wanted as much as we could possibly get, but obviously not more than we could afford so it was all about tailoring the budget. [Note: Though HBO won't divulge specifics, the show's budget is estimated at between $60-$70 million per season]

David Benioff (co-creator): We had one really intense conference call with the HBO brass. It was awkward: They said, "So, what are you guys talking about, an extra $500,000?" We said, "Noooo...." "You guys need a _million _dollars?" "Ummmm...."