A mysterious murderer has already killed seven people using the deadly venom of a snake from Martinique which causes immediate death with the victim's face turning into a horrible mask. A young and ingenious police lieutenant is called on the case

Fresh out of his degree in America, Carlo returns to Rome and his father hopes that he will take over the family business. Carlo, however, is passionate about rock music and spends his evenings at the disco with three friends who play with him. It was during a concert that Carlo met Elizabeth, an American girl who was studying ballet, and they fell in love. A love destined to encounter various difficulties, between her failure to admit her to the exam and the risk that his group will break up: the protagonist will be faced with a decision about his future.