During a space flight to Saturn, Colonel Steve West, along with two other astronauts are exposed to a blast of radiation. The blast seriously injures Colonel West and kills the other two astronauts. He later appears in a hospital back on Earth covered in bandages with his physician, Dr. Loring, confused about what is happening to him. As his physician leaves, Colonel West wakes up horrified, as he finds out the flesh on his face is melting away. In a fit of hysteria he attacks and kills a nurse and leaves the hospital in a panic. Loring and Dr. Theodore "Ted" Nelson, a scientist and friend of West, discover that the nurse's corpse is emitting feeble radiation, and realize West's body has become radioactive. Nelson believes West has gone insane, and concludes he must consume human flesh in order to slow the melting. Nelson calls General Michael Perry, a United States Air Force officer familiar with West's accident, and the general agrees to help Nelson find him; meanwhile, Colonel West is attacking and killing people that cross his path.