Alan Hale makes a teenage escape from Launceston when he gets work at Taronga Zoo in Sydney. It's the mid 1960s and Taronga's chief benefactor, Sir Edward Hallstrom, is pouring much of his fortune into acquiring new and exotic animals to add to zoo's collection.
Alan is apprenticed to the Head Keeper for monkeys and he's charged with cleaning out the cages each morning. He loves the zoo and his job, until he's outwitted by a family of thirty macaque monkeys who disappear over the zoo's walls and into the suburbs of Sydney.