St. Mariah's Hospital for the criminally insane achieves a new level in sadistic horror when a group of vampires that have been used as human guinea pigs begin to put the bite on Christmas party guests gathered for a grand (Guignol) ball. At the same time, an undercover reporter tries to rescue her incarcerated brother before he becomes the head vamp's latest tidbit.

A mental patient who believes he is Humphrey Bogart escapes from his institution and sets up in business as a private eye. Based on the the comic book series created by writers John Wagner and Alan Grant.