After a cavalry group is massacred by the Cheyenne, only two survivors remain: Honus, a naive private devoted to his duty, and Cresta, a young woman who had lived with the Cheyenne two years and whose sympathies lie more with them than with the US government. Together, they must try to reach the cavalry's main base camp. As they travel onward, Honus is torn between his growing affection for Cresta.

An unemployed construction worker heading out west stops at a remote farm in the desert to get water when his car overheats. The farm is being worked by a group of East European Catholic nuns, headed by the strict mother superior, who believes the man has been sent by God to build a much needed church in the desert.

Racial tensions threaten to explode when a black man is elected sheriff of a small, racially divided town in the Deep South.

An experiment on a simpleton turns him into a genius. When he discovers what has been done to him he struggles with whether or not what was done to him was right.

In Apache territory, a supply Army column heads for the next fort, an ex-scout searches for the killer of his Native wife, and a housewife abandons her husband to rejoin her Apache lover's tribe.

In this promotional short for Once a Thief (1965), composer Lalo Schifrin explains how he tries to make the music complement each particular scene, depending on the scene's mood.