Fabio, an orphan boy of obscure origins, is brought up in the household of nagging aunts, in a small country town. When he meets Don Segundo Sombra, a robust old gaucho, the boy-falls under the old man's enigmatic spell, and leaves his aunts to join the gaucho on his wanderings from estate to estate. They join a group of cattle drivers who make a living from herding, breaking in horses, and live in friendly companionship on the barren grasslands and pampas of Argentina.

During the years, Don Segundo transforms the boy into a hardy, self-reliant gaucho, whose affection for his mentor has remained undiminished.

Then, one day, news comes to Fabio. which threatens his self-contained, simple way of life…