Deltora Quest: Special Edition, Books 5-8

As the evil Shadow Lord tightens his grip on Deltora, it is up to three heroes to bring freedom back to this land of magic, monsters, and danger. Lief, Barda, and Jasmine must recover the lost gems of the Belt of Deltora at any cost. This will not be easy — beasts, traps, and terrors stand in their way. From the underwater lair of the ferocious Glus to the deadly mists of the Valley of the Lost, Lief, Barda, and Jasmine must summon up their deepest courage — and their greatest strength.
Book 5: Dream Mountain / Book 6: The Maze of the Beast / Book 7: The Valley of the Lost / Book 8: Return to Del