After having been framed by gamblers, Muggs is barred from riding in horse races. Snce he can no longer race, he takes up a collection so Ma Brown, who owns the horses won't have her stable foreclosed on. However, one of the gamblers involved in the frame falls for Ma Brwn's daughter, and decides to come clean and confess to the police about the frame. The other gamblers hear about it and set out to shut him up and discredit Muggs and Ma Brown once and for all.
Muggs, ordered by a judge to get a job "or else", is hired by a society matron as the chauffeur for her wacky family. An engagement party is thrown for the family's daughter, and the rest of the gang is hired as servants for the party. However, a valuable necklace disappears during the festivities, and all the gang is blamed for the theft.
Copy boys Muggs and Glimpy investigate a murder. They locate the ex-wife of the murdered man and become convinced she is innocent. They hide her from the police while they investigate.
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. Muggs see Spider, a new member of the gang, flashing a large amount of money around, and Muggs shrewdly turns toughie, boasting that he has a dishonorable discharge because of thievery. This leads Spider to confide in Muggs that he is the one who has been aiding in the theft of supplies from the warehouse, and...
Glimpy finds a necklace next to a dead body in an alley. His discovery leads to the gang getting mixed up in murder, intrigue involving a European royal family, and a killer who is after the necklace that Muggs has and will stop at nothing to get it.
Rocky Sullivan and Jerry Connolly were tough kids who grew up together in the toughest part of New York --- Hell's Kitchen. Early on, Rocky gets sent to reform school, where he learns how to be a first class criminal. Jerry, who had escaped from the law, goes straight and becomes a priest. As adults, they reunite in the old neighborhood: Jerry works with the kids who, like he and Rocky, could end up on either side of the law. Rocky has returned looking for a safe place to stay till he can get back into his old racketeering organization -- something that his old partner isn't anxious to have happen. Lots of rapid fire wisecracks, roughhousing ...
Gangster Baby Face Martin goes back to the East Side street where he grew up to see his mother, who denounces him as a murderer, and his childhood girlfriend who is now a streetwalker.