The film opens on Dr. Robert Morgan (Vincent Price) awakening to another bleak day of existence. It's been three years since a world-wide plague has changed Earth's population into zombie-like vampires and Dr. Morgan is the only man to survive, due to an immunity he acquired working in Central America years before. Finding food and fuel and looking for other possible survivors is his only existence, all the while battling hordes of blood thirsty vampires. Hope springs to life for Dr. Morgan when he is able to cure a young woman of her vampirism through a transfusion of his own blood. Can Dr. Morgan create a cure for the human race before the vampires get him?