Aliens from the constellation Hydra crash-land on the island of Sardinia. A prominent scientist, his daughter, several young technicians, and a pair of Oriental spies are taken hostage by the beings so they can use them to repair their spaceship's broken engine. With that done, they take off towards their home planet, taking the earthlings with them. However, the humans attempt to mutiny against their captors, inadvertently sending their tiny spaceship hurtling into the infinite beyond...

维克多（让·迦本 Jean Gabin 饰）是一名拳击教练，一次偶然中，他结识了名为安德烈（罗兰·勒萨弗尔 Roland Lesaffre 饰）的拳击手，安德烈虽然没有接受过拳击训练，但维克多发现他的身上隐藏着无限的潜能。维克多的妻子并不希望丈夫继续再待在这个充满了暴力和血腥的行业中了，当了解到了维克多太太的苦衷后，安德烈决定暗地里输掉比赛。
然而，命运将一个名为科琳娜（Marie Daëms 饰）的女人送到了安德烈的身边，让他深深的为她着迷，爱情使安德烈充满了力量，于是他取消了原定的计划，最终赢得了比赛。然而，很快维克多就发现，科琳娜的存在成为了安德烈职业道路上的绊脚石。