1960s Italian thriller directed by Umberto Lenzi. In Paris, wealthy businessman Jean Reynaud (Jean-Louis Trintignant) comes to the aid of his neighbour, Nicole Perrier (Carroll Baker), who is being abused by her boyfriend, Klaus (Horst Frank). When the pair become lovers, a complex plot is set in motion, orchestrated by Jean’s scorned wife, Danielle (Erika Blanc).