Francesco Di Narnali is a world champion billiards Italian and American, with a particular talent for spectacular performances, in particular to be able to pit fifteen balls to the pool with a broom instead of a stick; hence the nickname "Mr. Quindicipalle".

One day, Francesco went to the cemetery by his father and, attempting to steal the flowers to the graves he meets a woman named Sissi, who turns out to be a prostitute. Francis, having told relatives that he knew a certain Margaret, for one million and five hundred thousand lire, invites her to lunch at her home, calling her by the name of Margaret.

Sissi alias Margaret then tries to get rid of Francis, but it so happens that they meet again just to one of the performances of Francis, and they begin dating. He, more and more in love, even dedicates a new blow to the specialty five pins: un'ottavina nine banks, which he calls "Ottavina Princess Sissi".

Francis continues to practice at the pool to take part in a major tournament, but gradually begins to suspect something about the real work of Sissi. She, meanwhile, now in love with Francis, he decided to stop being a prostitute.

The day of the tournament Francis wins most of the meetings; Sissi decides to confess everything, but unable to see him because he was practicing for the final. But Francis shortly after the beginning of the final, after choosing to start with the specialty of American billiards, decided to leave the game before it even starts, congratulating his opponent. Full of anger goes away in his billiards room to romp on billiards.

When Francis finally calmed down, approaching the spirit of his father Renzo with a broom in his hand, the lights of a pool with the balls already in place. Renzo Francesco wants to put to the test: will post all fifteen balls with the broom and blindfolded. You understand then to be truly a champion born and Sissi to forgive his past.