A full history of the remarkable man, Dervis Korkut, who saved the book from the Nazi officers who sought it, is told in the December 3, 2007 edition of The New Yorker magazine. The article, entitled "The Book of Exodus" also by Geraldine Brooks, sets out the equally remarkable story of the young Jewish girl, Mira Papo, that Korkut and his wife hid from the Nazis just as they acted to save the Haggadah. In a twist of fate the story reveals how Mira Papo , then an elderly woman in Israel, brought about the safety of Korkut's daughter - from the Serbian genocide of the 1990's.The New Yorker article is not available online, but you can read the abstract here. As Ellen notes, "it would be pretty hard to beat this story, even in a novel!"
Background here and here.