3. The 39 Clues

Grace Cahill planned a surprise minutes before she died, a challenge if you chose to accept, which could lead you to unlimited power. Amy (14) and Dan (11) Cahill were just kids who were trying to get over the loss of their grandmother until they chose to just burn up 2 million dollars for a clue, the first of the 39 clues. Competing in a challenge with 6 other strong and rich teams, the kids thoughtthat they would not be able to even make it to the second clue, but did they? To answer this question and be part of the excitement , I suggest you read this amazing series written by 13 authors across 4 sections: 1. The Clue Hunt 2. Cahills vs. Vespers 
3. Unstoppable and 4. Doublecross. Also join the hunt at www.39clues.com