Antonio, Peppino and Lucia are three brothers who live in the country near Naples. Lucia's son, Gianni, goes to Naples to study medicine, but there he knows a ballet dancer. They fall in love and, when she goes to Milan, Gianni follows her. Informed of this and afraid that their nephew will stop studying, the three Caponi brothers leave for Milan to persuade Gianni to come back and continue studying and abandon the "Malafemmina" (bad girl).
Belle Duke, in order to get revenge on her former lover Philip Bang, organize his jail break. But instead of Philip is the Italian Felice Brianza, AKAS Felix, to escape. Now Felix is obliged to help Philip to escape. He will succeeded and from that moment on the two will join to defraud Belle. The swindle plot become more complicate when Felix falls in love for Philip's daughter.
The penniless Duke decides to participate in "Lascia o raddoppia", a TV quiz show, in order to win five million lira. Then two gangsters bet between themselves on his success and, alas, the Duke is kidnapped.
