The Civil War has ended, and Reynolds is seduced away from his career as a gambler by the lovely Dickinson. She wants him to help her recover a quarter of a million dollars worth of gold bars stolen by her late husband. The gold now lies on the bottom of Colorado's Platte River aboard a
sunken river boat and must be recovered before the Denver mint it was stolen from discovers it's missing, potentially destroying Dickinson's family's reputation. Reynolds agrees to do the job for $20,000 and teams up with Ossie Davis, a local blacksmith, and Walker, a buddy from the war who now
works as an inventor. The team heads for the Platte, unaware that they are being followed...