At the height of the Mexican revolution, El Chuncho and his gang of marauders hold up a train carrying ammunition. A mysterious young American passenger, Bill Tate, joins the gang and, nicknamed El Niño, helps them carry out a serious of savage raids to steal guns for a powerful rebel general, Elías. When the latter discovers that El Chuncho betrayed the revolution by not helping a beleagured rebel bastion but leaving it to its fate, he sentences El Chuncho to death. El Niño shoots the general, saving El Chuncho’s life – an act El Chuncho not wholly appreciates …