Read the book. Play the game. Solve the clues. Win the prizes.

Five minutes before she died, Grace Cahill changed her will. With one shaky signature she changed the destiny of the entire Cahill family, and perhaps that of the world as well. That signature would set into motion events that could mean the end of civilization as we know it.

“The children are old enough. They are our only chance,” Grace said to William, her attorney and closest friend for half her life. “If they don’t succeed, 500 years of work will have been for nothing.” And with that final statement, Grace Cahill closed her eyes for the last time.

About 400 family members came to her funeral. About 40 of them were invited to the reading of the will she had kept secret for so long and had signed so recently. William played a videotape she’d made months before, in case she decided to sign her secret, alternative will. In it she challenged her heirs to the most important task they would ever face. Each of them was given a voucher for a million dollars. They could choose to keep it, or they could turn it in and get a clue instead, the first of 39 clues that could lead one individual or one team to the most important treasure in the world, and make them powerful beyond belief. That clue would become their only inheritance — no money, no keepsakes, no property of any kind.

Which of Grace’s relatives chose to accept the challenge? Ian and Natalie Kabra were the first to get a clue. They looked like matching supermodels, but that exterior covered their selfish and ruthless natures. The five members of the Holt family were next, looking buff and muscular, like a family of GI Joes — even the mom looked like she should shave and start chewing on a big cigar. Alistair Oh, an elderly Korean man with a diamond tipped cane volunteered to be the third team. Irina Spasky, whose twitchy eye was responsible for her nickname, Spaz, said she’d play alone. Then Jonah Wizard, from the TV show Who Wants to be a Gangsta? sauntered up, with his silver chains, ripped jeans, and in-your-face attitude.

Finally, there were only two left who hadn’t decided. Amy and Dan Cahill were the two people closest to Grace, who’d loved her without caring about her money. Amy looked at her brother, “Remember,” she thought at him, “what Grace said to us: ‘You will make me proud.’ This is what she was talking about. This is our chance, our adventure.” She took his voucher and William’s lighter, and two million more dollars went up in smoke. The game had begun.

And now you can try to solve Grace Cahill’s mystery. Collect the 39 clues, visit the website, play the game, and win the prizes. Who knows? You could win and become the most powerful and richest person on earth!