The film is the third work in the "Ant-Man" series and the unveiling of the fifth phase of the Marvel Cinema Universe. The story takes place in "Avengers 4: After the Battle of the End,"Ant-Man" Scott Long (Paul Rudd) and Hope Van Dayne, the "Wasp Girl"(Evangeline Lilly) becomes a hero who saves the world. Dr. Pym and Janet, who has returned for a long time, also enjoy a peaceful semi-retirement life. However, due to an accident, they and Scott's daughter Cathy (Kathryn Newton) strayed into the quantum realm together and encountered Kang the Conqueror (Jonathan Majors), the strongest villain of the Marvel Film Universe, in this dangerous unknown world, and began an adventure that transcends the limits of their imagination.