Steven Bach is the author of two previous biographies, Dazzler: The Life and Times of Moss Hart and Marlene Dietrich: Life and Legend. Itwas while working on his biography of Marlene Dietrich that he became interested in Riefenstahl. For the two German women, born just months apart, could not have been more different.  One, an ardent anti-Nazi; theother, Hitler’s favorite filmmaker.