Antonio and Camillo are two ex-transformists who lead fraudulent lives, organising small frauds and deceptions. They often manage to escape justice thanks to the benevolence of Commissioner Malvasia, who is also a former schoolmate of Antonio's. The latter uses much of the money earned from the scams to finance the studies of his daughter Diana, who attends an expensive boarding school. Diana is unaware of her father's real activities, as he makes her believe he is a diplomat always travelling the world.
However, fate takes an unexpected turn when Antonio unwittingly swindles the commissioner's young son, Franco. The latter is engaged to Diana, and Antonio makes him pay a deposit for a fictitious job. When Franco discovers the true identity of Antonio, Diana's father, he is placed in a shady garage, then gets involved in illicit activities and ends up being arrested.
The situation will be resolved when Antonio receives a billion-dollar inheritance from America in an unexpected way. This will allow him to return the money to all the people he has swindled over the years. Meanwhile, Franco and Diana decide to get married, putting aside past misunderstandings.