This sequel to Kurt Neumann's The Fly (1958) follows Francois and Philippe Delambre, brother and son of Andre Delambre, who died as a result of his experiments with a matter-transmitting device in The Fly. It is now a dozen years later and Phillipe has just laid his mother to rest. She spent the final years of her life traumatized, having witnessed Andre's horrible death. Phillipe convinces Francois to tell him what happened and of the device that destroyed his parents' happy life together. Philippe vows to perfect the matter transmitter, so that all of the heartache and sacrifice by his parents will not have been in vain. He hires a friend, Alan Hind, to help. Phillipe is unaware that Alan has shady business connections and a dark secret in his own past. Alan conspires to steal the secret of the device, but first he must get rid of a detective who has come to arrest him for an earlier crime, and then eliminate Philippe, who doesn't know what Alan has done, only that he's hiding something. Through Alan's conniving the same disaster that befell Philippe's father now occurs to him: his body parts are transposed with those of a house-fly. The human-sized fly goes on a rampage, trying to catch Alan and get revenge for what has happened to him using what faculties he has.
Featuring: Vincent Price, Brett Halsey, David Frankham, John Sutton, Dan Seymour, Danielle De Metz