The characters played by Burt Lancaster, Frank Sinatra and Tony Curtis in the film are never identified by name.
The opening credits are handwritten, appearing as if cut out of the villain's notebook. Also during the credits, several faces of major and minor characters float by. The makeup worn by Tony Curtis, Burt Lancaster, Frank Sinatra and Robert Mitchum always manages to be on screen with each actors credit.
At the end of the last scene, the words "The End" (and production company and distributor credits) are superimposed. But then Kirk Douglas says in voiceover "Hold it! Stop!" The text now disappears again and the music score also stops. He continues: "That's the end of the picture, but it's not the end of the mystery." Scenes featuring four of the film's minor roles are now quickly reprised, with a suitable musical score, and the four actors each remove face masks and other makeup to reveal that the respective parts were played by Tony Curtis, Burt Lancaster, Robert Mitchum, and Frank Sinatra. Finally, Douglas similarly reprises five disguises that his character wore during the course of the story, and after the last one, reveals his face (which we had already seen when his character was undisguised). He says to the camera, "Ladies and gentlemen -- The End", and continues picking off bits of face mask glue while the musical theme concludes.
Although he plays the hero, George C. Scott receives sixth billing in the opening credits. Tony Curtis, Burt Lancaster, Robert Mitchum and Frank Sinatra, each seen very briefly, are all billed above him.