Tom Fowler watches in horror as his brother Ed is gunned down in cold blood. With his dying breath, Ed asks his brother to bring the killer to justice. Discovering that the hit was ordered by the city's top mobster, Marty Kirkland, Tom takes an undercover job at the racketeer's Broadway nightclub. Avenging his brother is momentarily forgotten when he falls in love with a gorgeous chorus girl, Nan Morgan. But Tom is shocked to learn that Kirkland is the flapper's boyfriend. Now with the life of the woman he loves at stake, Tom vows to take down the mob boss once and for all...even if he has to punch out every crook from Brooklyn to the Bowery.