Paper Towns by John Green

Quentin Jacobsen has spent a lifetime loving the magnificent Margo Roth Spiegelman from afar. So when she cracks open a window and climbs back into his life- summoning him for an ingenious campaign of revenge- he follows. When their all-nighter ends and a new day breaks, Margo has disappeared. But W soon learns that there are clues- and they’re for him. Embarking on an exhilarating journey to find het, the closer Q gets, the less he sees the girl he thought he knew.