Teenagers gathered in an old mansion are being murdered one by one. The survivors must discover who among them is the killer before he finishes off everybody.
A Scotland Yard detective is investigating a string of robberies and a murder, and the information he uncovers leads him to the estate of a wealthy but strange English family, who share their mansion with a group of nuns. The detective comes to suspect that neither the family nor the nuns is quite what they seem to be.
