United States Marshal A.A. Flint, retired, finds himself in a slow-moving wagon rumbling across the Wyoming territory in the company of a hot-tempered shrew and her prudish offspring.
Along the way, they stop off at the lawless and highly dangerous Town of No Return.
The good news is the trio expects to find a hidden fortune in gemstones awaiting them at their final destination.
The bad news is a death-dealing gunfighter known as the Man in Black is trailing them.