Scott Lang and Hope Van Dyne are dragged into the Quantum Realm, along with Hope's parents and Scott's daughter Cassie. Together they must find a way to escape, but what secrets is Hope's mother hiding? And who is the mysterious Kang?
Armed with a super-suit with the astonishing ability to shrink in scale but increase in strength, cat burglar Scott Lang must embrace his inner hero and help his mentor, Dr. Hank Pym, pull off a plan that will save the world.