There's only one rule in the race to find 39 Clues hidden around the world: Trust no one.

But when the hunt leads 14-year-old Amy Cahill and her younger brother, Dan, to Japan, their only chance to find the third Clue seems to lie with their unreliable uncle, Alistair Oh. Will they be foolish enough to make an alliance? With a Clue on the line, Amy and Dan might not have a choice. But in the Cahill family, trusting your relatives can get you killed.