Spanish book

Quentin has spent a lifetime loving the adventurous Margo from afar. So when she cracks open a window and climbs back into his life–dressed like a ninja and summoning him for an ingenious campaign of revenge–he follows. After their all-nighter ends and a new day breaks, Q arrives at school to discover that Margo, always an enigma, has now become a mystery. But Q soon learns that there are clues–and they’re for him, the closer he gets, the less Q sees of the girl he thought he knew.