When Mendes discovers that his code has been broken, he gives George a cup of coffee containing a truth serum, and George reveals that he and Mary are British spies. George, drugged, is left in his room, where he dreams of flying to Germany and giving Hitler a right hook. Eventually, he flees to join Mary on board a ship, but it has already left. So he hides in a motorboat which takes Mendes to a German U-boat, with the intent to torpedo British troop ships as well as the ship that Mary is on. George manages to get on board and alert Mary's ship over the U-boat's radio. After a series of chaotic incidents on board, where George accidentally launches the U-boat's torpedoes and thus tells the British Navy where to find it, he hides in one of the empty torpedo tubes. So when Mendes tries to torpedo Mary's ship, he shoots out George instead, who flies through the air and lands on the ship deck, thus reuniting with Mary.