Zm73 had a roll of film which he took to the World Camera shop in order to have the film made up into transparencies, slides if you prefer. The receipt he left with his fiancée Janet Portland, for times of trouble he said. I wonder why he did that, when he could just have easily left the receipt in the safe secreted behind the television set in his study? After all he took those American dollar bills from the safe, the rats having been nowhere near the safe, so the dollar bills were as fresh as ever. Certainly the receipt wasn’t so safe having been left in the safe keeping of Janet Portland. It must have been obtained from her, perhaps through her father Sir Charles. As “Mr. Carmichael” would need the receipt which would have been needed for identification of the roll of film, at the very least. And then the receipt given back to Janet, and the transparencies returned to the camera shop. Sir Charles Portland and his code breakers having been unable break the code in the slides because perhaps there isn’t one. Apparently breaking a code or cipher is a finite problem, and as far as the slides are concerned they don’t know there is a problem. And if there is, what level of reasoning it is set. But Sir Charles doesn’t believe that, it’s just that they haven’t thought of it yet, and doesn’t think it impossible for them to do so. So much for Sir Charles code breakers! That’s why they needed the unwitting services of ZM73, seeing as he was the last person to see Professor Jacob Seltzman, and therefore would know the meaning of the transparencies. ‘Do Not Forsake Me Oh My Darling’ so much for those words, because it would appear that unwittingly, Janet Portland betrayed her fiancé by handing over the receipt for the roll of film, and by that, placing the transparent slides into the hands of her father, who then put the transparencies into the hands of his code breakers, who couldn’t break the code because they didn’t know on what principle the code was based! If they had managed to break the code hidden in the slides, perhaps the services of ZM73 would not have been required!
Be seeing you