A new enemy. An even deadlier challenge. The NEW YORK TIMES best-selling series returns. The Clue hunt is over, but Amy and Dan's lives haven't returned to normal. They soon find themselves in a new global race, but this time everything's different. Their enemy is a mysterious organization that includes some of the world's most dangerous criminals. Known as the Vespers, they have rivalled the Cahills throughout history and have been waiting for an opportunity to attack. When a number of Cahills are kidnapped, it's up to Amy and Dan is rescue them. With few people they can trust, Amy and Dan are forced to ask themselves just how far they're willing to go to defeat the Vespers.