During a fishing vacation Barnaby and J. R. are hired by rancher Tim Carter to investigate a conversation overheard by Carter's daughter,Cassie, on her CB radio. Cassie believes that a hired hand, was the victim of foul play on his way out of town. J. R. uses his knowledge of the lingo used on CB radios to help Barnaby figure out that the disappearance is tied to a drug smuggling operation.