Reddit user CryptidLizard brings us a theory that posits Gamora has saved the "dusted" Avengers and taken them to the Soul World where she also resides. As we know, the comic version of the Soul Stone allows souls to exist within it. Though we don't see anyone else when Thanos visits Young Gamora at the end of Infinity War, that doesn't mean there aren't others there too (possibly hidden, or on the way). The theory continues that their souls are trapped in the Soul World with Gamora's, and their release will be at the hands of Adam Warlock and Captain Marvel. James Gunn has previously stated that Adam will not appear in Infinity War, but will be a major key in the cosmic universe. Adam is known for being one of Thanos's greatest enemies since he too can harness the power of the Infinity Stones. Seems like Avengers: Endgame will be the perfect entrance for him. Read the theory in full here!