from the back cover:
In our world today a hummingbird is a small, brilliantly coloured bird that lives in the tall trees of tropical forests.

In the far distant future, Hummingbird (Hummy for short) is a girl of sixteen who lives somewhere in the Galaxy, on a planet called Just Like Home. She has the name 'Hummingbird' in big letters on all her clothes, but she has never seen a real hummingbird. She has never seen any living animal or bird at all. The Book of Remembering says that there were once many animals on a planet called Earth, but that was before the Burning, a long, long time ago . . .