Stephen Westcott and Ed Martin scheme to put Jane Travers' wagon line out of business. They want to use it take over all the wagon- train traffic going west. Hoppy, California and Lucky must make sure that doesn't happen.
Jane Travers asks Hoppy to help protect her next caravan against robbers. Westcott and Martin are out to stop them and have their men dressed as soldiers to escort the caravan. The fake soldiers don't fool Hoppy and he and the Bar 20 boys foil that plan. Martin's men then capture everyone but Hoppy and send them off to the firing squad. Now Hoppy has to find a way to save them singlehandedly.
