Dozer, 'a long, slim, cold, shiny, metal bomb' has a gentle dreamy nature and can't muster any enthusiasm for the war. He doesn't understand the use of making such perfect bombs only to destroy them. When he is finally dropped from a plane, he looks down and sees a road full of refugees, including children, and realises that 'his death would be theirs'.
Dozer takes some deep breaths and finds that he can float - birds come to rest upon him, and he drifts towards the people, hoping he can help, but they are all afraid of him and run away. He keeps them company as they make their long and arduous trek, the threat of death always upon them. He manages to warn them when he senses another plane approaching, and they begin to trust him. Dozer becomes the enemy of the planes - rushing at them to prevent them harming the people - and 'the angrier he grew, the more he dilated, until he was bigger than the largest 'plane of all' and he eventually drives them away.
Dozer guides the refugees to safety, off the roads and through the countryside to a town by the sea, where they all board an abandoned ship. In a miraculous turn of events, thousands of birds descend and help to pull the ship out to sea. All is going well until the planes, filled with bombs, return to settle Dozer once and for all. Dozer leads them away from the ship and on a wild goose chase until they run out of fuel.
When he returns, he sees a submarine about to launch a torpedo to destroy the boat, and 'a great rage suddenly maddened him. In his ears was a rushing noise... He wanted, with all his might, to explode!' The book ends with Dozer dropping recklessly towards the submarine, as his head is filled with the words, 'The Target! The Target! THE TARGET!'