Midworld is a planet entirely covered by a rain forest three-quarters of a kilometer (almost half a mile) tall. Born is a member of the primitive human society that has lived peacefully on Midworld for hundreds of years, careful not to disturb the natural balance of the jungle. His people live in a gigantic tree called the Home Tree. When they die, they are ceremonially buried in another gigantic tree of a species called They-Who-Keep. Each of the locals forms a lifetime bond with a powerful and intelligent photosynthetic animal called a furcot. When they need to damage a plant they are familiar with, they communicate with it empathetically ("emfoling") to make sure it does not object.