The Iron Man is a gigantic, mysterious mechanical being of unknown origin. Made entirely of metal, he consumes various metals to sustain himself, searching the countryside for fences, tractors, and scrap. He acts out of simple necessity and instinct, possessing a silent intelligence and a remarkable ability to reassemble himself when broken into pieces.

Hogarth is a young boy living on a farm in the countryside. Unlike the adults in his community who react to the unknown with immediate hostility, he pays close attention to the strange occurrences around him. He spends his free time fishing and catching foxes, but soon takes an active role in dealing with the massive mechanical being wandering their land.

The Star Spirit is a colossal cosmic entity that lands on and covers the entire continent of Australia. Drawn to Earth by the noise and chaos of human conflict, it announces a terrifying demand to be fed living creatures. It possesses an immense physical scale that renders human military weapons completely ineffective.

Hogarth's father is a local farmer who acts as a representative of the adult community's reaction to the unknown. When confronted with a half-eaten tractor and the massive metal giant in the pouring rain, his immediate instinct is self-preservation. He organizes the other farmers to dig a massive trap to protect their livelihoods from the metal-eating giant.