Amy and Dan Cahill THOUGHT they were normal kids. But that was before they discovered they belong to the most influential family in history. Now they're on a worldwide hunt for the 39 Clues—the key to the Cahills' power. The journey will take them to some of the most dangerous locations on earth...and that's the easy part. They also have to evade the other Cahills who are following Amy and Dan's every move, and who will stop at nothing to make sure Amy and Dan are removed from the hunt...permanently.