A beautiful American woman infiltrates the home of a novelist and his wife so she can investigate the disappearance of her lover — who was her employers’ previous secretary — and soon finds herself the target of the couple's erotic desires and a murder plot.
A drug trafficker discovers his wife dead with her throat cut. He has no alibi so he takes his mistress to an abandoned hotel. As they become claustrophobic, the panicked criminal discovers more murders, one after another until strangers appear in the night and a sinister web of lies and secrets escalate out of control.
Jean Duprey and his wife Danielle are famous journalists with a special interest in unsolved mysteries. They receive a request of help by an old noble friend of Jean, Guillaume de Saint Lambert, who is about to die by an unknown illness. He lives, obviously, in ancient castle with his wife and the servants. Soon Duprey discover that his friend's wife is a witch (originally burnt in the 18th century) and that Guillaume is under her wicked influence. She practices the art of black magic and by making die slowly all members of the Saint Lambert family she gains eternal beauty. When Duprey breaks the marble casket containing the ashes of the witch she shows her real aspect before dying.
