Mission Hindenburg (The 39 Clues: Doublecross, Book 2)

In The 39 Clues: Doublecross, the powerful Cahill family faces a new and dangerous challenge as a mysterious figure known as The Outcast recreates some of history’s worst disasters and threatens their lives. Siblings Dan and Amy Cahill, along with their friends, must race against time to uncover the meaning behind cryptic messages and stop the impending catastrophe. With clues pointing toward a historic air disaster, they are forced to split up and take to the skies in a tense quest to prevent disaster before it’s too late.