‘Those were the pince-nez I found in Carlotta Adams’ handbag?’
‘Correct.’
‘Why did you think they might be Miss Carroll’s?’
Poirot shrugged his shoulders.
‘She is the only person connected with the case who wears glasses.’
‘However, they are not hers,’ I said thoughtfully.
‘So she affirms.’
‘You suspicious old devil.’
‘Not at all, not at all. Probably she spoke the truth. I think she did speak the truth. Otherwise I doubt if she would have noticed the substitution. I did it very adroitly, my friend.’
We were strolling through the streets more or less at random. I suggested a taxi, but Poirot shook his head.
‘I have need to think, my friend. Walking aids me.’
I said no more. The night was a close one and I was in no hurry to return home.
‘Were your questions about Paris mere camouflage?’ I asked curiously.
‘Not entirely.’
‘We still haven’t solved the mystery of the initial D,’ I said thoughtfully. ‘It’s odd that nobody to do with the case has an initial D—either surname or Christian name—except—oh! yes, that’s odd—except Donald Ross himself. And he’s dead.’
‘Yes,’ said Poirot in a sombre voice. ‘He is dead.’
I remembered another evening when three of us had walked at night. Remembered something else, too, and drew my breath in sharply.
‘By Jove, Poirot,’ I said. ‘Do you remember?’
‘Remember what, my friend?’
‘What Ross said about thirteen at table. And he was the first to get up.’
Poirot did not answer. I felt a little uncomfortable as one always does when superstition is proved justified.
‘It is queer,’ I said in a low voice. ‘You must admit it is queer.’
‘Eh?’
‘I said it was queer—about Ross and thirteen. Poirot, what are you thinking about?’
To my utter amazement and, I must admit, somewhat to my disgust, Poirot began suddenly to shake with laughter. He shook and he shook. Something was evidently causing him the most exquisite mirth.
‘What the devil are you laughing at?’ I said sharply.
‘Oh! Oh! Oh!’ gasped Poirot. ‘It is nothing. It is that I think of a riddle I heard the other day. I will tell it to you. What is it that has two legs, feathers, and barks like a dog?’
‘A chicken, of course,’ I said wearily. ‘I knew that in the nursery.’
‘You are too well informed, Hastings. You should say, “I do not know.” And then me, I say, “A chicken,” and then you say, “But a chicken does not bark like a dog,” and I say, “Ah! I put that in to make it more difficult.” Supposing, Hastings, that there we have the explanation of the letter D?’
‘What nonsense!’
‘Yes, to most people, but to a certain type of mind. Oh! if I had only someone I could ask…’
We were passing a big cinema. People were streaming out of it discussing their own affairs, their servants, their friends of the opposite sex, and just occasionally, the picture they had just seen.
With a group of them we crossed the Euston Road.
‘I loved it,’ a girl was sighing. ‘I think Bryan Martin’s just wonderful. I never miss any picture he’s in. The way he rode down the cliff and got there in time with the papers.’
Her escort was less enthusiastic.
‘Idiotic story. If they’d just had the sense to ask Ellis right away. Which anyone worth sense would have done—’
The rest was lost. Reaching the pavement I turned back to see Poirot standing in the middle of the road with buses bearing down on him from either side. Instinctively I put my hands over my eyes. There was a jarring of brakes, and some rich bus driver language. In a dignified manner Poirot walked to the kerb. He looked like a man walking in his sleep.
‘Poirot,’ I said, ‘were you mad?’
‘No, mon ami. It was just that—something came to me. There, at that moment.’
‘A damned bad moment,’ I said. ‘And very nearly your last one.’
‘No matter. Ah, mon ami—I have been blind, deaf, insensible. Now I see the answers to all those questions—yes, all five of them. Yes—I see it all…So simple, so childishly simple…’