Arenas Movedizas / The Shifting Sands (Deltora)

When the gems of the magic Belt of Deltora were stolen, the evil Shadow Lord invaded the kingdom and enslaved its people. Determined to rid their land of the tyrant, Lief, Barda, and Jasmine are on a dangerous quest to find the lost gems, which are hidden in fearsome places through the kingdom. They have found three gems. Now they must seek the fourth, hidden in a shimmering, barren waste, kept jealously by an unknown guardian.