But it was n't until mid-March 1942 that he had worked out the story in his head .
According to George Oppenheimer , who wrote the screenplay , the idea for the script came to him immediately after the attack on Pearl Harbor .
It was n't until mid-March 1942 that George Oppenheimer had worked out the story in George Oppenheimer 's head .
According to George Oppenheimer , who wrote the screenplay , the idea for the script came to him immediately after the attack on Pearl Harbor .