Six scientists arrive at the creepy Headstone Manor to investigate a strange phenomena which was the site of a mysterious massacre years earlier where 18 guests were killed in one night. It turns out that the house is the place of a satanic cult lead by a sinister monk who plans to kill the scientists who are inhabiting this house of Satan.
Kenny Everett
as Dr. Lukas Mandeville
Pamela Stephenson
as Dr. Barbara Coyle
Vincent Price
as Sinister Man
Gareth Hunt
as Elliot Broome
Don Warrington
as Stephen Wilson
John Fortune
as John Harrison
Sheila Steafel
as Sheila Finch
John Stephen Hill
as Henry Noland
Cleo Rocos
as Deborah Kedding
Graham Stark
as Blind Man
Pat Ashton
as Barmaid
David Lodge
as Inspector Goule
