WARNING: The following article contains major spoilers for Avengers: Infinity War, in theaters now.
Bruce Banner - well, to be precise, the Hulk - jetted off into space in Avengers: Age of Ultron and re-teamed with his fellow avenger in Thor: Ragnarok. As we know from the various trailers and footage for Avengers: Infinity War, he's making his grand return to Earth this weekend, but this begs the question of how he managed to find his way back home. After all, at the end of Ragnarok, he's on a spaceship alongside Thor, Loki, Valkyrie and the remaining Asgardian civilians with no indication that Earth is part of their itinerary.
A number of fan theories expected that Loki would be responsible for transporting Bruce Banner across the galaxy and back onto his planet -- perhaps in an act of self-sacrifice in the face of Thanos and the Black Order -- but that didn't end up being the case. Another Asgardian is, in fact, responsible for the Hulk's unceremonious return home: Idris Elba's Heimdall.
In the film's opening act, Thanos and the Black Order easily destroy the Asgardian refugee ship in an attempt to get the tesseract from Loki, who stole it from Asgard's treasury in Ragnarok. In an unexpected move, the Hulk is unleashed upon the Mad Titan and starts to deliver some heavy blows. The main antagonist truly shows his strength soon after, easily dismantling the Hulk in hand-to-hand combat and delivering what is the Jade Giant's first real defeat in a fight.
Down and out, the Hulk ultimately wasn't strong enough to defend his friends and peers. In one last heroic act before biting the dust at the hand of Thanos, Heimdall utilizes his ability to access the Bifrost to send the Hulk to Earth -- more specifically, to Doctor Strange's Sanctum Sanctorum. Crashing in through the roof of the building, we see a vulnerable, defeated Bruce Banner who instantly spreads the word of Thanos' plans and the danger of the Infinity Stones.
From then on, we only see Bruce Banner in Infinity War. The Hulk is effectively too scared of Thanos to even surface again, and that wasn't through lack of trying on Bruce's behalf. It's hard to say now when we'll see the Hulk again, but for now, he's at least back home on Earth.
Directed by Joe and Anthony Russo, Avengers: Infinity War stars Robert Downey Jr., Chris Evans, Chris Hemsworth, Mark Ruffalo, Jeremy Renner, Scarlett Johansson, Anthony Mackie, Paul Rudd, Elizabeth Olsen, Tom Holland, Benedict Cumberbatch, Chadwick Boseman, Chris Pratt, Zoe Saldana, Dave Bautista, Bradley Cooper, Vin Diesel, Tom Hiddleston, and Josh Brolin. The film is in theaters now.