In the year 1919, teenage Charlie Feehan dreams of a better life than the one his family lives in the Richmond slums of Melbourne. His father recently passed away, forcing Charlie to take on financial responsibilities while his mother, Mrs. Feehan, stays home to care for Charlie’s infant brother Jack.
To escape from the hardship of life in the slums, Charlie takes up running. One day, he skips school to compete in a race for the chance to win employment for local gangster Squizzy Taylor. Charlie wins the race, narrowly beating an aggressive boy named Jimmy Barlow. He also meets and befriends another racer, Norman “Nostrils” Heath. As Charlie’s prize, Squizzy Taylor employs him as a “runner”––a boy who runs errands for his organized crime ring. Mrs. Feehan forbids Charlie from working for Squizzy, but Charlie still intends to take the job because he is committed to improving life for his family.
Later, Nostrils and Charlie play football together. Nostrils is a far better player than Charlie, but Charlie enjoys Nostrils’s company so much that he doesn’t mind. Their game is interrupted by Jimmy Barlow and his friends, who steal Charlie’s football and try to attack him. Charlie runs away, and though Nostrils has a head start, he waits for Charlie to catch up so they can run away together. When Charlie starts working for Squizzy, Squizzy’s girlfriend Dolly gives Charlie a new pair of boots to replace his old ones. However, since his old boots are hand-me-downs from Mr. Feehan, Charlie is reluctant to give them up.
Charlie enjoys working for Squizzy, since the job grants him power and status, but he still struggles at home. Mr. Peacock, a timber worker who gives the Feehans free scrap wood, refuses to continue helping the family unless Mrs. Feehan does him sexual favors. She reluctantly gives in, leaving Charlie feeling betrayed on his father’s behalf. Despite his anger, he still leaps in to protect his mother a few days later, when a drunk Mr. Peacock is beating her in the kitchen. Charlie hits Mr. Peacock with a cricket bat, knocking the man unconscious, and runs to Squizzy for help. Squizzy ensures that Mr. Peacock will leave the Feehans alone and continue giving them firewood. When Charlie returns home, he and Mrs. Feehan reconcile.
Nostrils earns a spot on a local football team, and when Charlie goes to watch his friend play, he sees a pretty red-headed girl in the stands and learns her name is Alice. That week, Squizzy sends Charlie to collect debts, and one of the addresses on Squizzy’s list leads Charlie to Alice’s home. Mr. Cornwall cannot afford to pay back his debt, and his desperation makes Charlie realize that the power he enjoys from his job comes from victimizing desperate people like his own family. He talks to Daisy Maloney, a kind and friendly sex worker, who suggests that he use the money he earns unethically to do something good.
Meanwhile, Squizzy Taylor is growing more aggressive as he attempts to spread his influence by taking territory from rival gangs. Charlie recruits Nostrils to help him on a particularly dangerous liquor run, and afterwards the boys are jumped by Jimmy Barlow and his friends. Charlie runs away, leaving Nostrils to take the brunt of the assault, and when Charlie returns, Nostrils is beaten so badly Charlie has to bring him to the hospital. Charlie tells Squizzy Taylor about the attack, and when Squizzy makes clear he does not care, Charlie quits his job. He starts training with his neighbor, Mr. Redmond, to run in a professional footrace. Mr. Redmond accompanies Charlie to Ballarat, where the race is held. Charlie deliberately presents himself as a poor athlete to the spectators to stack the odds against him and increase the payout of betting on him. With Mr. Redmond’s help, Charlie bets all the money he made working for Squizzy on himself. Charlie wins the race and uses his winnings to buy the local timber yard for his community.