The 10-year-old Hubert Finn, known as "Fatty", lived in poor conditions in Australia in the 1930s. He and his friends stick together as they often have to defend themselves against the villain Bomer and his gang. Fatty wants a detector radio, but can't afford it. He has to raise money for it within a week, otherwise he won't get the radio ...
Fatty Finn is the six-year-old leader of a gang of kids in Woolloomooloo. They enter Fatty's pet goat Hector in the annual goat derby, but his rival Bruiser Murphy lets the goat loose before the race. After a series of adventures, Fatty finds the runaway goat and persuades a friendly aviator to fly him to the race-track in time for the main event.
Bobbie Morton is a gutsy heroine in the grand Australian tradition. She's a champion horsewoman who can hold her own amongst the men of the racecourse. As part of her adventures she must come to the bottom of a secret race-rigging scam, as well as fend off the advances of an amorous squatter.