[Warning: Spoilers for Game of Thrones Season 7 Episode 2 ahead!] 

So far, the most intense battle in the new season of Game of Thrones has undoubtedly been the open sea skirmish between Euron and Yara Greyjoy. While much of the scene must be credited to the strength of the performances of the aforementioned family— particularly Pilou Asbæk's menacing turn as Season 6's latest psychotic baddie—the battle would have been nothing without the tireless work of the visual effects technicians and stunt workers. 

Mark Mylod, director of the excellent episodes 2 and 3, admits that the biggest challenge of the boat sequence was “how to sell the idea that this was happening at sea, that they were floating on water, and yet we’re in a car park in Northern Ireland.”

Check out how they pulled it off in HBO's video below.

The first thing on the agenda was designing "The Silence." The boat was supposed to be huge, imposing, and more threatening than any nautical vehicle we had previously seen on the show. Yet, in actuality, it only had to be big enough to fit everyone who would be participating in filming the scene. That turned out to be quite a lot of people. In total, this meant room for 40 stuntmen, six cast members and all of the crew on the boat. Obviously, things got very crowded. It certainly didn't help that the surface of the deck was slippery with rain and there were actual fires burning on various parts of the boat.

According to showrunner David Benioff, fire is one of the hardest things to replicate on set, so the VFX team always chooses to employ real fire rather than CGI. The VFX team even went so far as to create ember guns to spray out across the set at incremental periods of time.

With the harsh elements of the set, effects, and production design, the brutal fight choreography was also challenging to pull off. Apparently, the visceral fight sequence was actually the product of the choreographer taking advantage of the scene's short cuts and simply asking his stunt people to “go nuts” for 10 seconds. On Game of Thrones, chaos begets chaos.

It's no wonder Theon Greyjoy lost his marbles.