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. Adrienne Carlyle and Michelle Esclapez star in this blood-soaked British gem.