When Sonny finds out that his friend Sid is planning to go to a military academy, he wants to go there as well. When Sonny's father reluctantly tells him that it would be impossible for him to pay for it, Sonny and Sid decide to go prospecting for gold in the hope of raising the money. They throw together some equipment and head out into the desert, where they discover that Sonny's young sister Mary Lou, determined to join them, has stowed away.