Underlord (Underland Chronicles Book 2)

Kira Lier thought she had escaped Underland and the monsters within, but her freedom was only an illusion, an extravagant lie created by the Underlords to keep her imprisoned. To break free and find Zeke and her friends, she teams up with Allyn, a mysterious young mage with a dangerous past.
When a bounty is put on their heads, she becomes the hunted, for the Underlords won’t let her slip through their grasp. She has been chosen by the Fates to save Underland because their world is dying, and their only hope lies in Kira surviving the deadliest game… the Labyrinth.