The East Side boxing champion Muggs answers a challenge to a fight against the West Side champ but just before the match he is kidnapped. His friend Danny Lyons takes his place and wins the fight, only to have Mugs believe that Danny was responsible for his kidnapping.

The East Side Kids discover that one of their own, Danny, is torn between staying and school and becoming a boxer, and is getting mixed up with gangsters.

Danny helps to capture a wanted criminal and receives a $200 reward. However, he has a falling out with the gang when they believe he should share the money with them. Complications ensue when the crook that Danny helped capture escapes from jail and comes looking for him.

Muggs and Glimpy, two East Side Kids in the army, return to their neighborhood, supposedly on furlough; actually, Muggs has been honorably discharged with a physical defect, but he tells no one of this. Danny, another East Side kid, is in jail because a large amount of medical supplies have been stolen from the warehouse where he works...

The East Side Kids find a young girl in the apartment of a man who has just been murdered. Believing her to be innocent, they hide her in their clubhouse while they try to find the real killer. The killer, however, used a baseball bat as his murder weapon, and the bat has the fingerprints of one of the gang on it.