Willard Parker, mine owner, openly tells his office manager, Tracey, and two other employees, Lew and Joe, that he suspects them of hi-grading and intends to get to the bottom of things. Tracey has Parker slain and incriminates Terry Blane, who is in love with Parker's daughter. And to make certain that Terry hasn't a chance at the trial, he instigates a lynch mob. Cisco and Pancho rescue Terry, and by some clever deduction, fast shooting and hard riding, prove Tracey and his men are murderers.