The Cahill's are on their second mission that a man called Outcast has created, he recreates something in history and the Cahill's must figure out the clues to stop the next disaster, this one being the Hindenburg explosion.
Publisher Annotation: CALLING ALL CAHILLS! Announcing a 39 Clues Superspecial adventure -- the gang is back, and called to investigate one of their own: Sinead Starling.