Annie Rooney is a young girl who spends her days wreaking havoc in the tenements with a gang of children and their rival gang, the Kid Kellys. They fight in the streets, accidentally scaring a fruit vendor's horse in the process. Annie's father is a respected neighborhood police officer, but her brother, Tim, is a member of the Big Kellys, a gang of older boys led by Joe Kelly. The gang raises money for themselves by selling tickets to an upcoming dance.