When miner Ben Pendleton strikes it rich, Ace Gibson has him killed but his men are unable to locate his mine. When California learns his cousin Ben has been murdered he gets Hoppy and Lucky to help investigate. Hoppy finds the clue left by Ben and finally solves the riddle and locates the mine. But just as they find the gold, Gibson's men arrive and make them prisoners.
Pirates on Horseback
Hoppy, Lucky and California search for a mine owned by Trudy Pendleton after it was taken from her by the swindling gambler Ace Gibson. They find the mine and Hoppy fights Gibson over it.
