Shep McNally is a marshal in the Yuma District of the Arizona Territory in the 1880s. He is assigned to track down and return hardened criminal, Dirk Langley, who has escaped from the Arizona Territorial Prison in Yuma.

The trail leads Marshal McNally to Tombstone, where he makes some new friends, among which is a woman he wants to make his wife, and some new enemies. His steel nerves and quick draw aid him in carrying out his mission and overcoming new obstacles along the way.