Dinehart played the youthful Bat Masterson who is the understudy of Wyatt Earp in learning the proper techniques of frontier law enforcement. Earp rarely calls him "Bat" but "Mr. Masterson" to teach the young man maturity. In a 1956 episode "Bat Masterson Again," Earp shows young Masterson on the proper use of a pistol. During this time Masterson was elected sheriff of Ford County, Kansas, which includes the county seat of Dodge City. Bill Tilghman had been denied the right to run for sheriff again. Earp as an appointed town marshal works with an elected sheriff, and their differences in jurisdiction do not cause any problems. Bat's brother, Ed Masterson, played by Brad Johnson, formerly the deputy sheriff on the Annie Oakley television series, is shot in an ambush by drunken Cowboys, and Masterson settles the score. When Earp finally comes to Tombstone, Arizona Territory, he lacks the working relationship with Sheriff Johnny Behan that he had in Kansas with Bat Masterson.