Michele "Mike" Lo Russo is a young Italian boxer who has moved to Hamburg to start a professional boxing career. When his German manager refuses to renew his contract, he returns to Trieste, where his older sister Anna lives. Orphaned at an early age, Anna has dedicated her life to her brother's success. His triumph in boxing seems to be the only way to a better life, both for him and for herself. Once again, Anna helps Mike by begging his old coach to train him again. But the hoped-for boxing matches fail to materialize and Mike becomes increasingly impatient. Bargni, a manager whom Mike met in Germany, persuades him to get involved in the illegal fight club business. After Mike hesitates at first, he finally accepts the tempting offer and enters a world without rules.