Sent to ferret out the criminal masterminds behind a profitable counterfeiting operation near the Mexican/Arizona border, the government agent and excellent sharpshooter, John Wyatt, goes undercover. Posing as John Rogers, Wyatt joins Doc Carter's travelling medicine show to find the dangerous gang whose boss is stone-cold Curly Joe Gale. But, on the Mexican side of the border, Wyatt approaches the captain of the Rurales to see if they can arrest Gale; however, two Mexican policemen arrest John instead. Can John Wyatt clear his name in time to protect Doc and his beautiful daughter, Linda, and bring the ruthless counterfeiter to justice?