There are two ways to explain this video from the Game of Thrones set in Spain: one a simple, spoiler-free version, and the other filled with information about the upcoming season and how it may or may not deviate from the books. Let’s discuss them in turn.
Spoiler-free version: Here’s a bunch of dudes getting lit the hell on fire. So very, very on fire. Someone points an industrial-grade flamethrower at them, hits “On” (this is how flamethrowers work, yes?), and moments later six or seven people are completely engulfed in said thrown flames. Filming Game of Thrones seems very intense and fun, what with this and all those makeout-crazed women chasing the actors around Spain. Get into show business, kids. I mean, if you like fire and kissing.
Spoiler-laden version: If the speculation is correct, this video depicts a scene from the fighting pits in Meereen. When you add that to the pictures of Daenerysy, Jorah, Daario and Missendei in the pit that hit the Game of Thrones fan site Winter Is Coming earlier in the week, it appears we can conclude (a) that Jorah’s storyline on the show will be another deviation from the books, as Winter Is Coming explained when the pictures went up; (b) that the above footage is from Daenerys’s wedding to Hizdahr zo Loraq; and (c) that the fire is coming from the mouth of Dany’s renegade dragon, Drogon, who shows up and wreaks havoc during the festivities, because no one can ever have a simple, casualty-free wedding on this show.
tl;dr Season 5 of Game of Thrones looks good
Source: Winter Is Coming