Strange coded messages lead the History Hunters to unravel the mystery of plundered Nazi loot that spans two generations and reaches around the world. Preston Masters and his two prep school friends, Kim Oh and Jay Wray, agree to join their friend, the world-renowned historian and antiquities dealer, Geoffrey Barnsworth, on a trip to Germany. A surprise tour of Bavarian castles used by the Nazis during the war is arranged by Geoffrey and includes a stay at a castle formerly owned by Reichsmarschall Hermann Goering. Aided by two new German friends whose family manages the castle, the schoolmates begin to unravel a mystery that has frustrated treasure seekers for nearly seventy years. Musty dungeons, hidden passages, and coded messages add to the intrigue -- and to the danger. A shadowy group of Nazis use threats, kidnapping, and even murder to keep their secrets safe from discovery. The History Hunters must use all of their ingenuity to escape the clutches of their cold-blooded foes and discover what these desperate men so carefully guard. At stake are the lost treasures of Europe and the very safety of the world.