As Scott Lang awaits expiration of his term of house detention, Hope van Dyne and Dr. Hank Pym involve him in a scheme to rescue Mrs. van Dyne from the micro-universe into which she has fallen, while two groups of schemers converge on them with intentions of stealing Dr. Pym’s inventions.

On Halloween night at a horror theme park, a costumed killer begins slaying innocent patrons who believe that it’s all part of the festivities.