Jacob is a young man in Los Angeles, California who lives a life of isolation by day and works as a security guard by night. This is due to a rare skin disorder developed in his youth that prevents him from being exposed to sunlight. His world opens up when he meets and falls in love with a local bartender and secret druggie, Mary, recently departing a relationship with a drug dealer. Beginning to crave blood, as everyday food no longer cures his hunger, Jacob suspects he may be a vampire, though his physician, Dr. Barnes, diagnoses him to be anemic. His condition worsens and he goes from consuming animal blood to depending on human blood for medical sustenance, a necessity which brings out his violent tendencies on people in the city.