Sue Morgan gets Hoppy and his friends to join their expedition looking for Indian artifacts. Expedition leader Atwood makes a deal with nearby cattle rustler Morgan to loot the Indian treasures instead and sell them. Hoppy is on to their plan and pretending to leave follows them. Not only is he outnumbered by Morgan's men, but California has himself about to be sacrificed in an Indian ritual.
| Actor | Role |
|---|---|
 William BoydHopalong Cassidy | Hopalong Cassidy |
 Andy ClydeCalifornia Carlson | California Carlson |
 Rand BrooksLucky Jenkins | Lucky Jenkins |
 Fritz LeiberChief Xeoli | Chief Xeoli |
 Douglas EvansGrimes Atwood | Grimes Atwood |
 Harry CordingMorgan | Morgan |
 Betty AlexanderSue Harmon | Sue Harmon |
 Francis McDonaldKane | Kane |
 Neyle MorrowJose | Jose |
| PPatricia TateTalu | Talu |
| LLouis FaustStark | Stark |
 Kenneth TobeyRed | Red |
| JJack QuinnMarshal | Marshal |
 Bill NestellPete | Pete |