Over eight hundred years earlier, The Great War changed the face of the earth, killing millions and destroying most of the world's technologies. Fortunately, a few remaining survivors passed down their technological knowledge to their descendants, so future generations could rebuild what had been lost.

Tinker's family was gifted with the safekeeping of the last known photos of the world, its people, plant life and animals. When Tinker realizes he's close to dying, he passes this duty on to the only one left in his family, a tiny robot named Boy.

After his father's death, Boy faces a world that only sees him as a robot, not someone with feelings and the ability to love, so he sets out to prove he's more than a bucket held together by bolts – so much more.