Prizefighter Jimmy Nolan, facing an opportunity to get a championship fight, is knocked out when he sustains what is apparently a permanent injury to his arm. From there, Nolan's path leads downhill. He is drawn into a romance with a nightclub entertainer, then is framed on a theft charge by a jealous suitor. After his prison term, Nolan makes a spectacular comeback in a fight which proves his courage and integrity, while disproving the fallacy about the old sports adage that "they never come back."

John is a timid student who works at the University Book Store. He is studying to be a botanist and has a secret crush on the lovely Julia. One day, one of his letters gets accidentally mailed and Julia receives it. When the letter says that he is a fraternity man and a big track star, Julia rushes right over to see him. But John is neither and Spike, Julia's boyfriend, is a track star at a nearby College. John does not want to enter the track meet so Julia tries to use psychology on him. That and a good wrestling hold makes John timidly agree to enter the race, but Spike still scares him.

A pilot carrying a valuable amulet is shot down over China by a ruthless Russian agent, who also wants the amulet.

Mary Brooks' father, who has been studying ancient tribes, falls into the hands of "the people of Zar, god of the Emerald Fingers." Tarzan helps Mary locate her father, rescues everyone from the High Priest of Zar, and takes Mary to his cave.