Park Avenue tycoon Mike Curran fears that a life of privilege has rendered his son Grant a weakling, and wants to toughen him up. He ships Grant off to his lumber operation so that the boy can learn the rugged logging business from the ground up. The foreman and manager of the camp have been robbing Curran blind for years, so when they learn of Grant's true identity, they assign him to the most dangerous assignments in an effort to get rid of him. What they and old man Curran don't know is that young pansy Grant is secretly a famous wrestler who fights under the name of the "Masked Marvel" and loves nothing more than a nasty fight. The crooks get much more than they bargained for when they go to war with Grant.
Athletic George O'Brien was a real-life hero and the heavyweight boxing champion of the Pacific fleet in World War I. He went on to become a top star of the silent screen. With the advent of talkies in the 1930s, he starred in dozens of Westerns and consistently ranked among the top-ten stars at the box office. He re-enlisted during World War II and was decorated several times for bravery.