Mary Bancroft (October 29, 1903, in Boston – January 10, 1997, in New York City[1]) was an American novelist and spy and a member of the Bancroft family, which at one time owned Dow Jones & Company. In 1942, while living in Switzerland, Bancroft was recruited by the Office of Strategic Services, and both worked and had a romantic relationship with Allen Dulles. Her most important work was with Hans Bernd Gisevius, a German military intelligence officer who supplied her with details of the 20 July plot to assassinate Hitler. After the war, Bancroft settled in New York and became a novelist.[1]