After a heist, the notorious jewel thief Rochard is murdered in a train. In Paris, his daughter Nicole Rochard, who is a stripper, is summoned by the police that wants to know the whereabouts of valuable diamonds that her father had stolen. She goes with her boyfriend Michel Aumont and tells that does not know anything about the missing diamonds. During the night, a blue eye masked man breaks in her apartment and threatens her, asking where the diamonds are. Nicole seeks protection with Michel but in the morning she finds contact lens in his bathroom and she suspects Michel may be the masked man. She seeks out her costumer Dr. Robert Matthews, who had hit on her, and she asks him if she could go with in to London. Matthews, who is married, brings Nicole to a house by the sea in a village and she poses of his wife. But soon the masked man comes to England and begins a crime spree. The Scotland Yard Inspector Baxter and his assistant are assigned to investigate the case.