See How ‘Game of Thrones’ Pulled Off an Epic Battle With Thousands of Ice Zombies (Video)

El Ranchito, a visual effects company in Spain, shows off its work

“Game of Thrones” is such a massive show that it’s always a question of how the crew manages to pull off such large set pieces. How do you plan a battle between thousands of ice zombies and three fire-breathing dragons?

A new video lays it all out. It was uploaded Friday by El Ranchito, a visual effects company based in Madrid that had previously brought many scenes to life for “Game of Thrones” fans, including the battle at Hardhome in Season 5 and the “Hold the Door” sequence in Season 6.

Set to the tune of the “Game of Thrones” theme, the five-minute compilation highlights a number of shots and how they were done, including ones that show thousands upon thousands of digitally-rendered wights and how the dragons interacted with them. The trick? A lot of layering and green screens.

Watch the compilation above.

We already got a glimpse behind-the-scenes thanks to HBO’s featurettes, which have been documenting the effects-heavy battles and sequences this season.

In one released following “Beyond the Wall,” the effects teams, along with showrunners D.B. Weiss and David Benioff, discussed the intricacies of the episode and shared their excitement about getting their long-awaited zombie polar bear.

The scenes beyond the Wall were shot on locations in Iceland and Belfast, which meant that the nature in Iceland had to be recreated elsewhere, and that crews were responsible for making winter look even more wintry.