According to Buck Henry, Del Close came into casting director Pat Harris's office in character with an electrical device. Close told Harris to touch the device which was rigged to electrocute her. Harris was taken to a hospital and still cast Close in the role.
The title refers to the original Orient Express train service that ran from Paris to Istanbul and became synonymous with intrigue and luxury travel often being used in spy (From Russia with Love (1963)) and mystery (Murder on the Orient Express (1974)) stories and movies. Though the route has often changed/shortened, the train no longer runs on the railroad system in Europe.