In 1939, the first of several hundred people -- students, professors, chess players, military officers, actresses, and debutantes -- quietly reported to a Victorian mansion outside London. This became "Station X", the Allies' top-secret center for deciphering enemy codes. Their task was to break the ingenious Enigma cipher, used by the Nazis for their high-level communications. The settings for the Enigma machine changed continually. The Nazi operators had 159 quintillion (159 followed by 18 zeroes) possibilities from which ...