A famous singer, Jenny Ascot (Ida Galli), visits her cousin Martha Caldwell (Carroll Baker) at her home in the Pyrenees. Caldwell has long been rendered mute after witnessing both her parents being killed in a train crash. While Ascot and Caldwell are travelling to Caldwell's home, they notice a strange man who seems to be following them. That night, at Caldwell's villa, Ascot hears noises coming from the garage, and when she investigates, is killed by an unseen figure.