Why the Hulk and Thor Are Fighting in the 'Ragnarok' Trailer

Thor and Bruce Banner’s Hulk might have been friends “from work” at some point in the Marvel Cinematic Universe, but the series’s third Thor-centric film, Thor: Ragnarok, will pit them against each another. The first official trailer for Thor: Ragnarok premiered Monday, showcasing the beginning of a Thor-Hulk throwdown of epic proportions. But why are these former allies fighting?

Last time anyone saw the Hulk was at the end of 2015’s Avengers: Age of Ultron. After the dramatic events of Sokovia, Bruce banished himself (in Hulk form) onto a Quinjet, headed who knows where. He didn’t seem to have much of a plan at that point. How Hulk managed to get himself to Sakaar — the gladiator planet ruled by the Grandmaster (Jeff Goldblum) that Cate Blanchett’s Hela banishes Thor to during Ragnarok — is a bit of a mystery. And so is Hulk’s sudden memory loss. As Thor points out with a hearty cheer, they’re “friends from work.” That doesn’t stop Hulk from attacking Thor moments later.

So, what’s up with that? Thor and the Hulk have fought alongside each other a few times now and are, as Thor would put it, brothers in arms.

Planet Hulk

Thor: Ragnarok’s gladiator-Hulk plot lines up nicely with Greg Pak’s 2006 Planet Hulk, in which the Avengers decided the Hulk was too much of a danger to Earth, so they sent him away to an entirely different planet. The Hulk becomes a gladiator and ends up the hero of said planet after freeing it from a tyrannical king.

Taika Waititi, the director of Ragnarok, is taking inspiration from Planet Hulk, including using the comic’s planet, Sakaar, as a place to maroon Thor. But Planet Hulk doesn’t include a plot where the Hulk seems to have lost his memories of working with the Avengers in the first place. Ragnarok seems to have taken the Hulk’s memories. Or, maybe, he’s just having some issues accessing Bruce’s memories.

How Did Hulk Get to Sakaar?

So, right now, here are the options: The Hulk’s gone through some trauma or some sort of brainwashing that’s erased his memories. It might have something to do with how he even managed to get to Sakaar in the first place. Or, maybe, the Hulk kind of recognizes Thor but is incapable of placing where he’s seen him before. There could be a lapse between Bruce Banner’s memories and the Hulk’s memories.

Or, maybe, just maybe, the Hulk is playing a game with the Grandmaster and the other citizens of Sakaar. Maybe, once the full trailer drops, audiences will be treated to a scene where the Hulk explains (in his own way) that he actually does know who Thor is, but didn’t want to get himself or Thor in trouble by not going through with the fight.

Unfortunately, it’s still unclear. But the question will probably be answered with the film’s first full-length trailer.

Thor: Ragnarok premieres in theaters November 3.