Orin and Ruth McKnight's May/December romance hits a rough spot when Bill Longley returns from a cattle drive with news that Orin's son from his first marriage died driving off rustlers. To make matters worse, Ruth's old beau has traveled all the way from Ohio to bring his former girlfriend home.

There is a card shark that didn't appreciate having his cheating be revealed, even if it was subtle. He is gunned down in the street. His brothers seek revenge, one brother is a little more cautious than the other. He wants to make sure they get the person who did the shooting or that the sheriff locates the person.

Outlaws besiege a small town where their leader is jailed. Pete: Jon Locke. Cliff: R.G. Armstrong. Ruth: Mae Clarke. Atkins: Fay Roope. Mac: Wright King.

Longley has been made a special marshal to the Texas town of Rio Nada. The area has been plagued by Mexican bandits who have used it to cross the border into the United States and raid the countryside. The gang is led by a mysterious leader known only as "El Sombro". When Longley captures an agent for El Sombro, he hopes to use the threat of hanging for the attempted murder of a deputy sheriff to force him to identify the illusive bandit chief. (Note to viewers: Best to first view "The Terrified Town", then "Sixgun Street", then "The Taming Of Rio Nada", as this is the order in which the events are meant to take place even though the episodes originally aired in the reverse order).