Ben and Adam are locked in jail, about to be hung for a crime they didn't commit. Joe and Hoss must find out why the witnesses to the alleged crime have perjured themselves before the execution takes place. They receive help from an unexpected source, a drifter called Lassiter who is searching for the men who committed a lynching in Kansas years ago.

The Cartwrights, with Hop Sing, finish a cattle drive in San Francisco. Ben warns the other men of the dangers of the big city. Nevertheless, some of the men are careless and naive. Two of the hired hands disappear, and Ben suspects that the men were shanghaied. With invaluable assistance from several of Hop Sing's cousins, the Cartwrights locate the missing men and break up the racket.