During his vacations, 12-year-old Manuel travels by train with his mother to the Sierra Tarahumara to spend a few days with his father, who works in the mountains with the indigenous people protecting nature. Manuel befriends Jesus, who takes him to his town and teaches him the customs of his own. Both children discover illegal loggers.
| Actor | Role |
|---|---|
 Pedro Armendáriz Jr.Ingeniero (padre de Manuel) | Ingeniero (padre de Manuel) |
 Helena RojoMadre de Manuel | Madre de Manuel |
 Ernesto Gómez CruzBenito | Benito |
 Aurora ClavelMujer de Benito | Mujer de Benito |
| PPaco MauriRosendo | Rosendo |
| AArturo AdonayManuel | Manuel |
| JJesús Bernabé QuinterosJesús | Jesús |
 Ramón MenéndezDurán (talamontero) | Durán (talamontero) |
| GGerardo SoubletteTendero | Tendero |