Title: The Lie Tree
Author: Frances Hardinge
Published: Macmillan Children's Books, May 2015 (UK)
Publisher's description: The leaves were cold and slightly clammy. There was no mistaking them. She had seen their likeness painstakingly sketched in her father's journal. This was his greatest secret, his treasure and his undoing. The Tree of Lies. Now it was hers, and the journey he had never finished stretched out before her.
When Faith's father is found dead under mysterious circumstances, she is determined to untangle the truth from the lies. Searching through his belongings for clues she discovers a strange tree. A tree that feeds off whispered lies and bears fruit that reveals hidden secrets. The bigger the lie, and the more people who believe it, the bigger the truth that is uncovered.
But as Faith's untruths spread like wildfire across her small island community, she discovers that sometimes a single lie is more potent than any truth.