Full spoilers follow for Ant-Man and the Wasp and Avengers: Infinity War.
Ant-Man and the Wasp may have lightened the tone of the Marvel Cinematic Universe after the heavy proceedings of Avengers: Infinity War, but in the end the second solo film for the MCU’s tiniest superhero delivered yet another gut-punch to fans everywhere. Let’s break down exactly what happened!
The film’s story ends with Paul Rudd’s Scott Lang, Evangeline Lilly’s Hope van Dyne, and Michael Douglas’ Hank Pym rescuing Michelle Pfeiffer’s Janet van Dyne from the Quantum Realm, where she’d been lost since the 1980s. Janet, a.k.a. the original Wasp, emerges from that strange microverse a changed woman, now in command of some kind of mysterious powers which enable her to temporarily, at least, help Ghost keep it together. Quite literally, as that character had spent most of the film slowly being torn apart by her own phasing powers.
Source: IGN.com Ant-Man and the Wasp End Credits Explained