Alberto Tango is the owner of a small and shabby detective agency in the area close to Naples. His collaborator is Corrado, naive boy with some problems of mental stability. Tango lives by his tricks, often at the limit of legality, to fill the huge debt that he has contracted with the cynical Rava, his ex former employer and current creditor. Tango receives a call from Sergio Tudisco, an important industrial man. He wants to hire him to find her daughter Olga, rebel girl run away. Tudisco gives Tango the sum that would solve the problems with Rava. Tango accepts after a hesitation.