David is surprised by his mother with news that he gets to travel to South Tyrol to visit the family of Karl Baumgartner during spring break for his fourteenth birthday present. Karl lived with David's family the previous summer as an exchange student and the two became friends. On the flight over the Atlantic, David befriends another boy, John, traveling to visit his father, who is stationed in southern Germany with the army. During the flight, they encounter a strange, dark man with an odd tattoo on his wrist. When they arrive in Austria, a great adventure begins as the boys are called upon to use their wit to try and escape treacherous circumstances.