Update: Deadline is now reporting that Ruffalo is nearing a deal with Marvel to reprise the role of Bruce Banner / Hulk in Thor: Ragnarok, confirming this week's earlier rumor that the actor would appear alongside Chris Hemsworth in the third Thor film.

Original story continues below...

One of the biggest mysteries following Avengers: Age of Ultron is the whereabouts of The Hulk. After taking part in the climactic battle in Sokovia and helping the Avengers to defeat Ultron, Hulk takes off in a Quinjet for parts unknown. Even Black Widow and Nick Fury have no idea where he went. Well, you won’t have to wait that much longer to find out. A new report says that The Hulk will actually co-star in Thor: Ragnarok and will be teaming up with the Norse God to save the day.

JoBlo is reporting that Mark Ruffalo has joined the cast of Thor: Ragnarok where he will appear alongside Chris Hemsworth, Tom Hiddleston and Jaimie Alexander. Moreso, their sources say that the bulk of Ragnarok will take place on a “distant planet” that is “not Asgard and not Earth” (I mean, if we’re splitting hairs here, Asgard isn’t a planet, it’s a realm, but OK).

This would certainly seem to indicate that somehow Hulk has made his way into another dimension and isn’t just chilling on a beach somewhere in Fiji. But, will this launch the long-rumored Planet Hulk storyline? Those rumors have dogged Marvel for years, as everyone from Kevin Feige to Joss Whedon to James Gunn have denied the rumors of a Planet Hulk movie, but is this a clever way of making a Planet Hulk movie without actually making a Planet Hulk movie? And, how do you make a Planet Hulk movie and still have it be about Ragnarok, the Norse Apocalypse?

JoBlo continues that they aren’t sure of the ratio of Hulk-to-Banner in the finished film, but that Ruffalo will “feature prominently” in one or both of those characters.

As the superhero arms race heats up, it’s not surprising to see Marvel continue with what they started in Captain America: Civil War, and continuing to crossover their superheroes in each other’s films. Neither Hulk nor Thor were in Civil War, so it makes some sense that those two characters would find time to cross paths in Ragnarok.

Just recently it was announced that Taika Waititi (What We Do In the Shadows) would be directing Thor: Ragnarok and with that major piece of business done, it could be that casting is close to underway. Though filming is not expected to begin until late next year, so this seems ambitious.

Thor: Ragnarok is set to open in theaters on November 3, 2017.

The 50 Coolest Marvel Easter Eggs

More From ScreenCrush