the fascist mice who are nibbling away at our country while we're busy fighting a good war." Stewart believed Hollywood had punished him for years for his political views and felt vindicated by the assignment, declaring that "here was my compensation for the sabotage of my radical attempt to do my bit ...". The script was the proudest moment of his entire career. Stewart, however, had extensive problems adapting the novel for the screen, and filming—originally due to begin in June 1942—was delayed for several months while he worked on the screenplay. He consulted with the Bureau of Motion Pictures in the U.S. Office of War Information, an agency of the federal government created in June 1942 to promote patriotism and warn the public about domestic spying. Spencer Tracy had been cast as the male lead in the film just days after MGM purchased the rights to the novel. George Cukor was chosen to direct in late April 1942 because he had dealt well with troubled and headstrong actors in the past, and Tracy was considered a difficult actor to direct. Bronisław Kaper, who had come to MGM in 1935 from Nazi Germany, was assigned to compose the film score. William H. Daniels was named the cinematographer. Katharine Hepburn joined the cast in mid-April 1942 after Stewart sent her a copy of the unfinished script. Hepburn was fascinated by the character of Christine, and felt that doing the film would be a way of contributing to the war effort. MGM executives did not want Hepburn attached to the picture, feeling it was an inappropriate follow-up for her (first) previous pairing with Tracy in Woman of the Year (1942), but Hepburn insisted, and MGM relented. Hepburn showed some concerns with Stewart's redrafting of the script, in that he toned down the novel's love story, placing more emphasis on the character of O'Malley and the action. She asked for more romance in the film. Although Hepburn had spent much of the prior year searching for scripts with equally strong male and female parts for her and Tracy, she now requested that the O'Malley role be restored to the function it served in the novel (where O'Malley is impotent, troubled, and despairing of love) and her own part expanded. Film producer Victor Saville threatened to resign if the changes were made, and Spencer Tracy supported him, which led to the changes being rejected.