Bart substitutes a rock-filled suitcase for a fortune in gold to foil hijacking plans of phony sheriff Dan Trevor (Peter Breck).

In New Mexico, Beau Maverick is taken for over $4,500 ($4,000 of which belong to his friend Jerry O'Brien) by con artists Warren and Crippen and Warren's granddaughter Rosanne. Beau tries to recover the money and even takes the threesome to court, but they outsmart him every time. Beau is so demoralized by the constant defeats, he believes he has disgraced the Maverick name - until Rosanne tells him that her grandmother was a Maverick.