This year marks 21 years since the September 11, 2001 terrorist attacks against the U.S.

With a huge presence in front of and behind the camera, Branagh's fingerprints are all over "Murder on the Orient Express," including the area of songwriting, a place he's only ventured to once before. Now, with "Murder on the Orient Express," Branagh has put his pen to paper once again for the lyrics to "Never Forget," the haunting end credits song for which Doyle wrote the music. In a phone conversation with the actor-filmmaker this week, Branagh discussed "Never Forget," an ethereal ballad sung by his co-star Michelle Pfeiffer. The song serves as an elegy for the tragic loss of a character at the heart of the film's narrative. "It reminded me of moments in my youth when I used to hear my granny get upset," Branagh recalled.