The 39 Clues series gets treacherous. Book 6 takes Amy and Dan across 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.
Could Amy and Dan's biggest enemy be . . . a friend? Book 6 in the bestselling The 39 Clues series challenges everything you thought you knew about the Clue race.

Fourteen-year-old Amy Cahill and her younger brother, Dan, head to the Land Down Under to discover what their own mother and father knew about the hunt for the 39 Clues. But following in their parents' footsteps brings up lost memories for Amy so awful that she can't share them . . . even with Dan. Haunted by the ghosts of their past, chased by deadly competitors, Dan and Amy can't see who is an enemy and who is a friend. Their blindness leads to a terrible mistake . . and the death of a hidden ally.