Spell of Undoing, The (Book #1): Quentaris Chronicles #2, The: Quest of the Lost City

Calamity has befallen the city of Quentaris! Quentaris is uprooted - city cliff-face, harbour and all - and hurled into the uncharted rift-maze. Lost and adrift in the endless labyrinth of parallel universes, encountering both friends and foe, the city faces a daunting task. Somehow Quentaris must forge a new identity and find its way home.