Jimmy Dixon, pursued by a band of Mexicans, changes clothes with a tramp, who takes off on his horse. Four miles later, Jimmy walks onto the Double-O Ranch, from which he had been thrown off four years before by his dad, who had blamed Jimmy for something that his twin brother Duke had done. Duke, home from college, took over the ranch when Mr. Dixon became ill, and has run it into the ground. When Duke goes to the bank to repay a debt to Jimmy, he rides onto Phoenix with all of the ranch money.

Betty's father has an invention that looks like a fancy camera; it emits an ultra-lavender ray that temporarily rids the ray's target of inhibitions. To test it, Betty's father zaps Charley hoping his newly-aberrant behavior will cause Betty to end her affections for the milquetoast. Dad's plan backfires: the invention works perfectly, Charley gets a backbone, and Betty loves her new forceful man. However, Charley's courage and lack of a superego get him in trouble with the law. He goes on trial for assaulting a bullying police officer. Is Charley going up the river leaving Betty high and dry?