A young man, Andrea, from the bourgeoisie of Lugano, with power in high finance, falls in love with a beautiful pianist, Antonia. Antonia leaves his fabulous career for the love she feels for him. Soon the beautiful women leads him in a growing state of jealousy which leads to a murderous obsession. The young man tells his passion to an unknown, in an airport while waiting for a flight.

Arrived in Naples to work in the Doumenec family's factories, engineer Stefano Mascardi meets Rita, wife of Junio ​​Doumenec, eldest son of the industrialist Alfredo Doumenec, founder of the factory of the same name. A liking is born between the two but, soon, Stefano learns that Rita is involved in shady deals. The woman is in fact the lover of an unscrupulous man, Mr. Detoledo and, in agreement with him, has recently stolen an important industrial formula from Doumenec. When Mr. Detoledo is found killed, Stefano receives a mysterious phone call. A woman arranges to meet him in the very place where Detoledo's body is found by the police. It's a trap? Maybe... But in the meantime, next to Mr.'s body. Detoledo, a photograph portraying three girls is found. One of these is Rita Doumenec..

The relatives of a young rebellious hier to a fortune (Dean Reed), who spends most of his time on a yacht, try to have the kid interned as a madman, but are mysteriously killed one by one, in the family's villa. A girl (Stefania Careddu), lost at sea and saved by the young man, will also have some surprises in store… This giallo was filmed in 1969 but not released until two years later and remains extremely rare.