Harry Balbo is a weak and cowardly salesman, who witnesses a violent crime in an dark alley. He is convinced that the killer is the Head Ripper serial killer but no one believes him when he tells the Police that it was a beautiful woman vampire who ripped off the head with her bare hands. He becomes obsessed with finding her and, through sheer chance, discovers that one of his neighbors, the wheelchair-bound Strickland, is a vampire hunter who has been tracking vampires for years after being attacked by one in Vietnam. Using a computer program made for tracking serial killers, they begin to work out where she hunts. However, when Harry finds her, he cannot bring himself to kill her. He builds a steel cage and locks her inside.
By the time he realizes that he cannot change her nature and gives up, offering himself to her to feed upon, she no longers wants to kill him. Instead she turns him. When they start to hunt together, Strickland knows he will be one of their first kills.