1970s British horror starring Christopher Lee and Peter Cushing as a police officer and a psychiatrist who work together to try and get to the bottom of strange happenings on a remote Scottish island. The island is home to an orphanage that comes to the attention of police colonel Charles Bingham (Lee) when three of its trustees are found dead in a short space of time. Though initial evidence suggests that the deaths were suicides, Bingham is suspicious and enlists the help of Sir Mark Ashley (Cushing) to try and get to the bottom of the mystery.