La Notte dei Dannati plot
Jean Duprey and his wife Danielle are two journalists with a special interest in unsolved mysteries. They receive an assignment from an old friend of Jean, the Count Guillaume de Saint Lambert, who has fallen from an unknown illness and is on the point of death. He lives with his wife and servants in an old castle. Soon, Duprey discovers that his friend's wife is a witch, who was originally burned in the 18th century, and that Guillaume is under her evil influence. She practices Black Magic and by exterminating all members of the Saint Lambert family, she will gain eternal life. Duprey breaks the marble casket, which contains the witch's ashes, and will witness a series of gruesome ritual murders along with Danielle.