 The screenplay by Donald Ogden Stewart is adapted from the novel Keeper of the Flame by I. A. R. Wylie . Hepburn plays the widow of a famous civic leader who has suddenly died in an accident , while Tracy portrays a former war correspondent who intends to write a flattering biography of the dead man , only to find that his death is shrouded in mystery . Screenwriter Stewart considered the script to be the finest moment of his entire career , feeling vindicated by the assignment as he believed that Hollywood had punished him for years for his political views . Principal filming began in the last week of August 1942 , four months after the release of the novel , published by Random House . The entire picture was filmed on a sound stage , with no location shooting . Hepburn had already begun her extramarital affair with Tracy , and due to his heavy drinking , she became his constant guardian during filming . 
