Humberto Fuentes is a wealthy Mexican doctor whose wife has recently died. Close to retirement, he decides to take a trip to see one of his proteges who is serving in the impoverished mountain villages. Once there, Fuentes finds out from a blind woman that his former student was killed by "the men with guns." The local police dismiss this rumor which, in turn, makes Fuentes committed to discovering the fate of, as it turns out, more than one of his students.