Frances Hardinge

Faith's father has been found dead under mysterious circumstances, and as she is searching through his belongings for clues she discovers a strange tree. The tree only grows healthy and bears fruit if you whisper a lie to it. The fruit of the tree, when eaten, will deliver a hidden truth to the person who consumes it. The bigger the lie, the more people who believe it, the bigger the truth that is uncovered. The girl realizes that she is good at lying...

In a world where anyone can cast a life-destroying curse, only one person has the power to unravel them. Kellen does not fully understand his unique gift, but helps those who are cursed, like his friend Nettle who was trapped in the body of a bird for years. She is now Kellen's constant companion and his closest ally. But the Unraveller carries a curse himself and, unless he and Nettle can remove it, Kellen is a danger to everything - and everyone...