Sandy and Marcy Catlin come out of the bank after having made their first payment on their $500 loan Slim Sherman cosigned. A local drunk but big man Charlie pushes them off the boardwalk causing the diminutive Sandy to try fighting him but with little success as Slim steps in. The Catlin brothers are a trio of murderous outlaws on the run and headed to Laramie which spells trouble for their step-brother Sandy who they call The Runt, his wife Marcy and acting sheriff Slim Sherman. Lou, Rix, and Colby Catlin have little use for Sandy except as a means to an end. Holding Marcy hostage they force Sandy to go back to work in the stage line office so he can feed them information on coaches carrying money. When that doesn't net them enough money, they force Sandy and Marcy to help them rob the bank. Sandy's job is to ensure Slim is out of the way while they do it or Marcy's life is forfeit but they don't trust Sandy and they want to make sure that Slim isn't able to follow them, permanently.