On the Wyoming range, a good horse is a man's best friend. But for Clint Adams, the big black named Duke is more like his partner. So it's no surprise that when a wealthy Texas rancher offers a ton of money for Duke, the Gunsmith turns him down flat. When Clint is knocked unconscious and Duke disappears, he has a good idea who is to blame. The Gunsmith heads for Texas and a showdown with the rancher, but to no avail: Duke has vanished. With the aid of the thief's daughter, Clint tracks him to the wild herds of the panhandle not knowing if he'll ever see his "partner" again!