It was too late to hand in my roll to-day. I had to hurry home to Kensington so as not to be late for dinner. It occurred to me that there was an easy way of verifying whether some of my conclusions were correct. I asked Mr. Flemming whether there had been a camera amongst the dead man’s belongings. I knew that he had taken an interest in the case and was conversant with all the details.

To my surprise and annoyance he replied that there had been no camera. All Carton’s effects had been gone over very carefully in the hopes of finding something that might throw light upon his state of mind. He was positive that there had been no photographic apparatus of any kind.

That was rather a set-back to my theory. If he had no camera, why should he be carrying a roll of films?

I set out early next morning to take my precious roll to be developed. I was so fussy that I went all the way to Regent Street to the big Kodak place. I handed it in and asked for a print of each film. The man finished stacking together a heap of films packed in yellow tin cylinders for the tropics, and picked up my roll.

He looked at me.

“You’ve made a mistake, I think,” he said, smiling.

“Oh, no,” I said. “I’m sure I haven’t.”

“You’ve given me the wrong roll. This is an unexposed one.”

I walked out with what dignity I could muster. I dare say it is good for one now and again to realize what an idiot one can be! But nobody relishes the process.

And then, just as I was passing one of the big shipping offices, I came to a sudden halt. In the window was a beautiful model of one of the company’s boats, and it was labelled “Kenilworth Castle.” A wild idea shot through my brain. I pushed the door open and went in. I went up to the counter and in faltering voice (genuine this time!) I murmured: