According to Marcie Muir, the book is concerned with an eight-year-old narrator named Tom: 'The book is set in the Victorian diggings of "Bendiggerat", and Tom is obsessed with the desire to see the "ornithorhynchus paradoxus". When poking around the sandy bank of a creek he finds a large nugget, which he covers with sand until he can bring his father to help him move it. But when they reach the spot, it is gone, and Tom realizes a bushranger had been watching him and had stolen it. The story revolves around the attempt to recover the nugget and Tom's involvement with the bushrangers and the troopers' ('The Lure of Gold: Boy's Adventure Stories and the Australian Gold Rushes' 93).