Two bounty hunters join forces to bring an outlaw to justice.

In the post-Civil War Southwest, two bounty hunters set out after a sadistic outlaw, Indio, for whom a $10,000 reward is offered. One of the hunters is a stranger known only as "the man with no name"; the other, Col. Douglas Mortimer, is a former Confederate Army officer whose sister committed suicide after being raped by Indio. The two men first encounter each other in El Paso and prepare for a showdown, but instead they decide to join forces in tracking down Indio and splitting the reward. To win favor with Indio, the stranger organizes a jailbreak and frees the outlaw's best friend. After joining Indio's gang, the stranger double-crosses Mortimer by persuading Indio to ride in a direction other than the one expected by Mortimer. The colonel, however, has anticipated the stranger's strategy and waits for Indio and his gang at their destination. Mortimer then proceeds to ingratiate himself with the gang leader by opening a safe stolen from the El Paso Bank. After patching up their differences, the two bounty hunters prepare to make off with the contents of the safe. But Indio captures them, and after failing to find out where they have hidden the money, he conceives a plan for eliminating both the bounty hunters and his own henchmen, thereby securing all the money for himself. He sets free Mortimer and the stranger and orders his gang to kill them. When the bloody gun battle is over, only Mortimer and the stranger are still alive. Mortimer, aided by the stranger, avenges his sister's death by killing the cowering Indio. His mission completed, Mortimer rides off, leaving the stranger to deliver all the dead bodies and collect the bounty money.