"Amy and Dan's rivals have been preparing for the hunt for the 39 Clues their entire lives. Eleven-year-old Natalie Kabra is deadly with a dart gun. Fifteen-year-old Hamilton Holt can hack into any computer network on earth. Yet Amy and Dan didn't even know about the Clues until their grandmother's funeral. How are they supposed to survive a worldwide hunt that's been claiming the lives of famous Cahills for the past 500 years?"