On the audio track, director John Frankenheimer explains that an alternate ending was screened to test audiences. They reacted so negatively to it that a different ending was prepared.
Principal difference between the ending in the released version and this one: While Sam and Vincent discuss the case, Dierdre waits outside the restaurant. She begins to leave, is kidnapped by her former IRA associates and presumably killed.
The alternate ending is presented in letterbox format, with the timecode still visible.
