Hoppy uses an incriminating letter and a crooked card deck to hunt down the murderers of a small boy's parents.

Hoppy's efforts to save a young woman's mine from swindlers are complicated when Red Connors develops amnesia and claims to be a Spanish nobleman.

While investigating raids by white men dressed as Indians, Hoppy and Red find valuable copper on the Indians' land.

While chasing a murderer, Hoppy and Red are locked in a shrine with an emerald religious statue during a Mexican festival.