The German navy refitted the merchant ship Atlantis with weapons hidden in phony deckhouses and side structures.  Using its disguise as a freighter, the Atlantis stalked the ocean for over 600 days in 1940 and 1941.  She captured or sank 22 ships until cornered and sunk by the British.  Bernhard Rogge was the captain of the Atlantis throughout its service.  This is the story of what he and his crew did.