At the reading of their grandmother's will, Dan and Amy Cahill are given the choice of receiving a million dollars or uncovering the 39 clues hidden around the world that will lead to the source of the family's power, but by taking on the clues, they end up in a dangerous race against their own family members. Maze of bones is the first in a series of 10 books. The publisher offers an online game as well.

A Clue found in Book 3 sends Amy and Dan jetting off to find out just what's behind the fierce rivalry between the Tomas and Ekaterina branches of the Cahill family. Was a Clue stolen from the Tomas branch? Where is it now? And most important, can Amy and Dan get their hands on it before their rivals do?

Amy and Dan cross the oceans on the trail of a famous aviator, but they find more than they're looking for. Their enemies are becoming more vicious, and the truths they discover more crushing than ever.

"Amy and Dan Cahill have been located once again, this time in the company of the notoriously unreliable Alistair Oh. Could they have been foolish enough to make an alliance? Spies report that Amy and Dan seem to be tracking the life of one of the most powerful fighters the world has ever known. If this fearsome warrior was a Cahill, his secrets are sure to be well-guarded . . . and the price to uncover them just might be lethal."--Publisher.

Throughout the hunt for the 39 Clues, Amy and Dan Cahill have uncovered history's greatest mysteries and their family's deadliest secrets. But are they ready to face the truth about the Cahills and the key to their unmatched power? After a whirlwind race that's taken them across five continents, Amy and Dan face the most the difficult challenge yet -- a task no Cahill dared to imagine. When faced with a choice that could change the future of the world,...

Amy and Dan Cahill have been located once again, this time in the company of the notoriously unreliable Alistair. Spies report that Amy and Dan seem to be tracking the life of one of the most powerful fighters the world has ever known. If this fearsome warrior was a Cahill, his secrets are sure to be well-guarded.

Where are Amy and Dan Cahill? The two kids were last seen in Egypt, hunting for one of the 39 Clues that could make them the most powerful people on earth. But no one has seen the siblings since. Has ruthless Irina Spasky finally tracked them down? Or worse ... the Madrigals?

A million dollars, or a clue? Police report a break-in at an elite hotel, and the suspects sound suspiciously like Amy and Dan. There's a car and speedboat chase and an angry mob! When there's a clue on the line, anything can happen.

"Amy and Dan hit the high seas as they follow the trail of some infamous ancestors to track down a long lost treasure. However, the real prize isn't hidden in a chest. It's the discovery of the Madrigals' most dangerous secret and, even more shockingly, the true identity of the mysterious man in black"--Amazon.com