Far away from their native France, two men are in trouble in a Mexican town. One is a gentle missionary monk, Brother Benoît, the other is a tough stubborn boxer named Antoine Capella. Brother Benoît has saved a chimp he calls Mookie and who has become his pet but the trouble is that it is a talking monkey, which is the reason why a groups of scientists want to take it away from him. As for Capella, he has refused to lose a rigged fight and now a gang of badmen are after him to punish him. When the two men are forced to leave the town, they decide to travel together to Mexico. The road will be long and eventful...