The first problem he faces is the appearance of an anonymous letter. The letter alleges that Gastner's deputy, Thomas Pasquale is stopping Mexican nationals and demanding money before they can go back over the border. Then other people come forward, saying that they also received the letter. It's a dilemma for the sheriff. He doesn't want to accuse the young deputy and find he's innocent; he doesn't want to let him go unpunished if he's guilty. Gastner decides to investigate the matter for himself.

Before he can get to it, however, Gastner is called to the scene of a bizarre accident. A man had been fixing a tire on his backhoe when the chain holding the tire must have slipped. The tire dropped and crushed the man to death. The victim was Jim Sisson, and he and his wife Grace, were notorious for their marital spats -- the police had even been called to their home three times that same day. Grace refuses to say what the arguments were about saying that it was between her and Jim. As the investigation continues, it becomes clear that it wasn't an accident after all, and Gastner tries to solve the case before another innocent life is lost.