Maurice Maïeux lives in a small modest flat near Paris together with his father, Marcel. Marcel used to be a successful heavy-weight boxer 20 years ago, however, would not take part in sham fights. Consequently he was made to disappear from public by hitting him below the belt during one of the fights, him thus being impotent and having to walk on crutches for the rest of his life. His son Maurice is 18 years old, 1.90m tall and weighs 100 Kg. Be it for the sake of taking revenge or for the mere wish that his son should reach more in life that he himself did, Marcel's heart-felt wish is that Maurice should become a successful boxing champion - and one day even world champion ! Yet, Maurice fights against being patronized by his father. In fact, he devotes all his love to music. His father tries to change his mind by getting his son a girl : Nora, a very sexy and feminine woman, however, married. When Maurice and Nora are on the point of making love, Nora's husband shows up and brutally beats up Nora. Maurice feels forced to act. With a professional punch he hits his opponent who, by accident, beats his head against a table and falls down dead. From this very moment on, Maurice's life becomes turbulent...