Some of these changes have obvious superficial reasons. The choice of an American instead of an English star involved a number of alterations. For example, Mr Joseph Cotten quite reasonably objected to the name Rollo. The name had to be an absurd one, and the name Holley occurred to me when I remembered that figure of fun, the American poet Thomas Holley Chivers. An American, too, could hardly have been mistaken for the great English writer Dexter, whose literary character bore certain echoes of the gentle genius of Mr E. M. Forster. The confusion of identities would have been impossible, even if Carol Reed had not rightly objected to a rather far-fetched situation involving a great deal of explanation that increased the length of a film already far too long. Another minor point: in deference to American opinion a Rumanian was substituted for Cooler, since Mr Orson Welles’ engagement had already supplied us with one American villain. (Incidentally, the popular line of dialogue concerning Swiss cuckoo clocks was written into the script by Mr Welles himself.)

One of the very few major disputes between Carol Reed and myself concerned the ending, and he has been proved triumphantly right. I held the view that an entertainment of this kind was too light an affair to carry the weight of an unhappy ending. Reed on his side felt that my ending – indeterminate though it was, with no words spoken – would strike the audience, who had just seen Harry die, as unpleasantly cynical. I admit I was only half convinced; I was afraid few people would wait in their seats during the girl’s long walk from the graveside and that they would leave the cinema under the impression that the ending was as conventional as mine and more drawn-out. I had not given enough consideration to the mastery of Reed’s direction, and at that stage, of course, we neither of us could have anticipated Reed’s brilliant discovery of Mr Karas, the zither player.

The episode of the Russians kidnapping Anna (a perfectly possible incident in Vienna) was eliminated at a fairly late stage. It was not satisfactorily tied into the story, and it threatened to turn the film into a propagandist picture. We had no desire to move people’s political emotions; we wanted to entertain them, to frighten them a little, to make them laugh.