In order to stop a potentially deadly missile, she shrunk herself small enough to fit between the molecules of titanium plate — and while she was successful in disabling the projectile, it was a sacrifice.
Michelle Pfeiffer, of course, has an important history in comic book movies, having famously played Catwoman in Tim Burton’s Batman Returns.
She’s been there for the equivalent of decades in the normal world, but Ant-Man and The Wasp will see the heroes on a mission to bring her back.
She hasn’t returned to the “genre” since, but is now coming back in a big way.