Gripped by civil war and ruled by the underworld, Southern Mexico is in turmoil. In this climate of violent and unrest, the betting sport of choice is "pit fighting", a brutal and sometimes deadly martial arts contest. The local champion is a mysterious "gringo" the punters call Jack. For five years in an almost Zen-like state of consciousness, Jack has been taking on and defeating all comers with brutal efficiency. But he is a man with no past; he does not even know his real name. Gradually he pieces together the fractured memories of an evil past. He realizes the path to redemption lies in the destruction of the underworld figures who once guided him.