In Lilurrian, one of the eight elf worlds, tree spirits and elves live in harmony with nature in a beautiful forest. The Great Library, the centre of elf learning and culture, lies at its heart. When the Navigator sets out to mine the crystals of Lilurrian, the whole forest is under threat of destruction. How can Agnil, the half-elf, prevent this disaster? Who is the Navigator and what does he really want?