A string of cattle rustling seems to be stymieing Roy and the local authorities, because it seems the livestock is vanishing into thin air. However, when a group of strangers start arriving in town and insist that Dale buy their cheap supply of meat, Roy gets suspicious that they're behind the thefts.

After having a conversation with the chief of the Acuna Indian tribe about his suspicion of someone stealing from a mine on their reservation, Roy finds the chief murdered and several samples silver ore from the mine gone. Calling upon Dale, Pat, and the sheriff to help him investigate, they soon discover that the prime suspect is the owner of a local trading post.