Though the first trailer for Avengers: Endgame left us with plenty of questions, the footage did offer some confirmation, in case it was needed, that Scott Lang makes it out of the Quantum Realm, and probably pretty early in the picture, too.
Of course, what remains to be seen is how exactly the character makes his escape, and the internet has its suggestions, from the the time vortexes teased in the post-credits of Ant-Man and the Wasp, to some sort of failsafe device that would allow Scott to return to the normal world without assistance from the other side. But supposing Ant-Man does need some help to escape the Quantum Realm, one post on Reddit suggests that it could come from his last movie’s antagonist, Ava Starr, aka Ghost.
Indeed, it’s worth remembering that the whole reason for Scott’s latest trip into the Quantum Realm was to harvest quantum energy to help Hannah John-Kamen’s character remain stable. It therefore seems likely that Ava knew where Scott and the gang were at the time of The Decimation (assuming, of course, that she survived), and so the theory suggests that she might head over to the site when she doesn’t hear word from the people helping her.
From here, it’s argued that since Ghost has some experience of her own with quantum phenomena, she might be able to help Scott out, either by bringing him back through the Quantum Tunnel or by sending instructions his way.
Though there’s probably only so much runtime that the Russo Brothers would give over to a supporting character from Ant-Man and the Wasp, there’s a certain logic to this theory, even if it may be a little anticlimactic to resolve Scott’s cliffhanger in such a straightforward manner. After all, shouldn’t Avengers movies be about different parts of the MCU interacting, rather than our heroes collaborating again with their old co-stars?
Regardless, we’ll find out if Scott has any associates left to give him a hand when Avengers: Endgame comes out on April 26th, 2019.