Doug’s story about the evening of Frank’s murder also clarifies a few things. First, it helps us understand why Frank gave Doug everything in his last-minute will. Then it explains why everyone was wondering what Frank's last words to Doug actually were. The resolutions to both mysteries trace back to that fateful Hay-Adams conversation. Frank was planning to murder Claire; of course Frank had to change to whom his assets would go in the event of his death. Doug was the last person he trusted. And, it appears the last thing Frank said to Doug was that Claire needed to die. It’s possible Frank wanted Doug to pick up his murderous intentions if he failed.