Twelve-year-old Gem lives with her gold-fossicking grandfather at Needy Flat, a rough and poverty-stricken place on the New South Wales central tableland. Orphaned in infancy, Gem has been raised almost entirely by her grandfather, and has had little contact with other children. Gem is bossy and quick and wilful, and she and her grandfather express their mutual affection via playful taunts and banter. Gem and her grandfather decide she should attend school, since her grandfather has taught her all that he can. And so Gem comes to attend the one-teacher school, run by Frank Gray, the new school master, and meet the other students. Meanwhile, a bushranger is on the loose in the vicinity.