The most spectacular episode in “Game of Thrones” almost never happened.

We’re talking about Blackwater, the ninth episode of Season 2. It features a huge battle between the forces of King Joffrey and his would-be replacement, Stannis Baratheon, in the bay of King’s Landing.

That single hour of television ended up costing $8 million. Which is about $2 million more than the already stupendous amount spent on your average “Game of Thrones” episode.

The show’s writers, David Benioff and Dan Weiss, had to plead with HBO for the extra money. Without it, those spellbinding battle scenes would not have been possible.

“We almost had no battle at all,” Benioff told Entertainment Weekly. “For budgetary reasons, we came very, very close to having all the action take place off-screen, the way plays have handled battle scenes for a few thousand years.”

“To our minds, the entire season builds to this clash, and if we didn’t see any of it, we were undercutting the story and shortchanging the audience.”

Weiss and Benioff faced a similar problem in Season 1. They had to avoid showing a huge battle at the end of the season because there simply wasn’t enough money.

“This whole story of Blackwater goes back to the first season because we were supposed to have that battle with Tyrion and we ended up not able to shoot it,” Benioff said. “And so we had him go down to friendly fire early.”

The pair didn’t want that to happen again. They decided the Blackwater episode was important enough to warrant facing the bosses at HBO.

“We went down on bended knee. ‘Just this once. Please.’ We were genuinely nervous about it for the whole time until we finally wrapped it,” Benioff said.

“The impressive thing about the conversation where we went in asking for more money, a considerable sum, in order to shoot the Blackwater battle — we didn’t get everything we wanted — but (they didn’t ask), ‘Will this attract more viewers? Is this something that’s going to pump ratings?’

“It’s all about why this story needs this big battle. ‘You guys were able to do the first season successfully without major, big-scale battles, why does this one need to have one?’ And so it was really a long conversation about how the second season all builds towards Blackwater.”

Money wasn’t the only hurdle, of course. Blackwater was filmed in pretty rough conditions.

“I think pretty much a month straight of night shoots, which is just tough for anybody unless you’re a vampire,” Benioff said.

“There was an incredible amount of mud. It’s tough for the crew, but then when you actually see it on screen and see how good it looks, you see the way the weather affects people. You see the wind blowing their hair and the rain coming down. None of that’s faked.”

The end result was undeniably spectacular. But was it worth an extra $2 million? Come to think of it, is “Game of Thrones” worth $6 million per episode?

This article originally appeared on News.com.au.