The Duc de Richleau (Christopher Lee) is concerned by the disappearance of his young friend Simon (Patrick Mower) from the social scene. Accompanied by former army colleague Rex (Leon Greene), de Richleau discovers that Simon has joined a group of Devil worshippers, led by the evil Mocata (Charles Gray). Through de Richleau's attempts to wrest Simon from Mocata's influence, Rex becomes romantically involved with Tanith, another member of the cult.
Actor: Charles Gray
Actor: Christopher Lee
Actor: Rosalyn Landor
Actor: Patrick Mower
Actor: Sarah Lawson
Actor: Leon Greene
Director: Terence Fisher
Actor: Paul Eddington
Actor: Russell Waters
Writer: Richard Matheson
Actor: Gwen Ffrangcon Davies
Actor: Nike Arrighi
Music: James Bernard
Producer: Anthony Nelson-Keys