There was a dangling plot thread at the end of Taika Waititi's Thor: Ragnarok that Marvel fans were left to question: Did Bruce Banner sacrifice his humanity to be the Hulk for good? Hulk, we had learned, was in his hulking green warrior form for the better part of two years, fighting battles on the trash planet of Sakaar. He reverts back to Banner (Mark Ruffalo) in the movie, but the scientist has such little control over his power, he fears that when he becomes Hulk once again to fight Hela (Cate Blanchett), that he'll stay Hulk for good.
Well, he doesn't. The first shot that we get of Mark Ruffalo in the Avengers: Infinity War trailer that arrived this week, he's in human Bruce Banner form. He's dazed and disheveled, and seems deeply confused by what is happening to him -- a common state for Banner after a stint as the Hulk. But he's definitely human... and it's not just in that initial shot. He stays as Banner for numerous scenes -- even in Wakanda.
How is Hulk able to switch back to Bruce Banner, his human alter ago? It's a good question, and one that could be answered just by saying that Banner was wrong in Thor: Ragnarok, and his fear of being stuck as the green rage monster was unfounded.
Then again, there could be magic in play here. Pay attention to the Avengers: Infinity War footage and you will notice that Banner has landed in the Sanctum Sanctorum, the Manhattan-based headquarters of Doctor Strange. There's a hole in Strange's ceiling, suggesting that Hulk fell from above. Did he fall as far as from the galaxies, when we last saw him with Thor (Chris Hemsworth) and Loki (Tom Hiddleston)? Or does Strange teleport him, similar to the way he transports Thor and Loki to Europe to see their father before he passes on in Ragnarok?
In the process of encountering Hulk, Doctor Strange may revert the beast into Banner -- for his own protection. And we also know that Banner isn't stuck as Banner forever, because in the final shot, Hulk is running with Team Cap as they rush to defend Wakanda. Here, just watch the full trailer again:
So, heading into Avengers: Infinity War, Hulk can be Hulk, but he can also be Banner. It's strange that they raised that potential conflict in Thor: Ragnarok, only to diffuse it immediately. It makes me wonder if there was a bigger plan in place that somehow got deflected. We'll know more when Infinity War reaches theaters on May 4, 2018.