Luigi Maietto aka "Chinaman" escapes from prison. As soon as he is free he assigns immediately two henchman to murder the inspector whose testimonal once led to his prison sentence. Inspector Tanzi is left for dead but survives. The local newspapers cover up for him and pretend the assassination had succeeded. When Tanzi gets better, his superior wants him to hide in Switzerland. But Tanzi defies him because he intends to make sure himself that Maietto is put back in prison. He goes for it.