In a post-epidemic nightmare world, scientist Robert Morgan (Vincent Price) is the only man immune to the plague which has transformed the entire population of the Earth into vampire-like creatures. He becomes the monster slayer that vampire-society fears. Curing one of them, Ruth (Franca Bettoja), with a transfusion of his blood gives him hope for the future. It is a short future, however, since the other vampires quickly find and kill him. This dark tale, based on Richard Matheson's even darker novel "I Am Legend," was later remade as The Omega Man with Charlton Heston in the Vincent Price role.