It was a few days later, when we were sitting at breakfast, that Poirot flung across to me a letter that he had just opened.

‘Well, mon ami,’ he said. ‘What do you think of that?’

The note was from Lord Edgware and in stiff formal language it made an appointment for the following day at eleven.

I must say that I was very much surprised. I had taken Poirot’s words uttered lightly in a convivial moment, and I had had no idea that he had actually taken steps to carry out his promise.

Poirot, who was very quick-witted, read my mind and his eyes twinkled a little.

‘But yes, mon ami, it was not solely the champagne.’

‘I didn’t mean that.’ 

‘But yes – but yes – you thought to yourself, the poor old one, he has the spirit of the party, he promises things that he will not perform – that he has no intention of performing. But, my friend, the promises of Hercule Poirot are sacred.’

He drew himself up in a stately manner as he said the last words. ‘Of course. Of course. I know that,’ I said hastily. ‘But I thought that perhaps your judgment was slightly – what shall I say – influenced.’

‘I am not in the habit of letting my judgment be “influenced” as you call it, Hastings. The best and driest of champagne, the most golden-haired and seductive of women – nothing influences the judgment of Hercule Poirot. No, mon ami, I am interested – that is all.’

‘In Jane Wilkinson’s love affair?’

‘Not exactly that. Her love affair, as you call it, is a very commonplace business. It is a step in the successful career of a very beautiful woman. If the Duke of Merton had neither a title nor wealth his romantic likeness to a dreamy monk would no longer interest the lady. No, Hastings, what intrigues me is the psychology of the matter. The interplay of character. I welcome the chance of studying Lord Edgware at close quarters.’

‘You do not expect to be successful in your mission?’

‘Pourquoi pas? Every man has his weak spot. Do not imagine, Hastings, that because I am studying the case from a psychological standpoint, I shall not try my best to succeed in the commission entrusted to me. I always enjoy exercising my ingenuity.’

I had feared an allusion to the little grey cells and was thankful to be spared it.

‘So we go to Regent Gate at eleven tomorrow?’ I said.

‘We?’ Poirot raised his eyebrows quizzically.

‘Poirot!’ I cried. ‘You are not going to leave me behind. I always go with you.’

‘If it were a crime, a mysterious poisoning case, an assassination – ah! these are the things your soul delights in. But a mere matter of social adjustment?’

‘Not another word,’ I said determinedly. ‘I’m coming.’

Poirot laughed gently, and at that moment we were told that a gentleman had called.

To our great surprise our visitor proved to be Bryan Martin.

The actor looked older by daylight. He was still handsome, but it was a kind of ravaged handsomeness. It flashed across my mind that he might conceivably take drugs. There was a kind of nervous tension about him that suggested the possibility.

‘Good morning, M. Poirot,’ he said in a cheerful manner. ‘You and Captain Hastings breakfast at a reasonable hour, I am glad to see. By the way, I suppose you are very busy just now?’ 

Poirot smiled at him amiably.

‘No,’ he said. ‘At the moment I have practically no business of importance on hand.’

‘Come now,’ laughed Bryan. ‘Not called in by Scotland Yard? No delicate matters to investigate for Royalty? I can hardly believe it.’

‘You confound fiction with reality, my friend,’ said Poirot, smiling. ‘I am, I assure you, at the moment completely out of work, though not yet on the dole. Dieu merci.’

‘Well, that’s luck for me,’ said Bryan with another laugh. ‘Perhaps you’ll take on something for me.’

Poirot considered the young man thoughtfully.

‘You have a problem for me – yes?’ he said in a minute or two.

‘Well – it’s like this. I have and I haven’t.’

This time his laugh was rather nervous. Still considering him thoughtfully, Poirot indicated a chair. The young man took it. He sat facing us, for I had taken a seat by Poirot’s side.

‘And now,’ said Poirot, ‘let us hear all about it.’

Bryan Martin still seemed to have a little difficulty in getting under way.

‘The trouble is that I can’t tell you quite as much as I’d like to.’ He hesitated. ‘It’s difficult. You see, the whole business started in America.’

‘In America? Yes?’ 

‘A mere incident first drew my attention to it. As a matter of fact, I was travelling by train and I noticed a certain fellow. Ugly little chap, clean-shaven, glasses, and a gold tooth.’

‘Ah! a gold tooth.’

‘Exactly. That’s really the crux of the matter.’

Poirot nodded his head several times.

‘I begin to comprehend. Go on.’

‘Well, as I say. I just noticed the fellow. I was travelling, by the way, to New York. Six months later I was in Los Angeles, and I noticed the fellow again. Don’t know why I should have – but I did. Still, nothing in that.’

‘Continue.’

‘A month afterwards I had occasion to go to Seattle, and shortly after I got there who should I see but my friend again, only this time he wore a beard.’

‘Distinctly curious.’

‘Wasn’t it? Of course I didn’t fancy it had anything to do with me at that time, but when I saw the man again in Los Angeles, beardless, in Chicago with a moustache and different eyebrows and in a mountain village disguised as a hobo – well, I began to wonder.’

‘Naturally.’

‘And at last – well, it seemed odd – but not a doubt about it. I was being what you call shadowed.’

‘Most remarkable.’ 

‘Wasn’t it? After that I made sure of it. Wherever I was, there, somewhere near at hand, was my shadow made up in different disguises. Fortunately, owing to the gold tooth, I could always spot him.’

‘Ah! that gold tooth, it was a very fortunate occurrence.’

‘It was.’

‘Pardon me, M. Martin, but did you never speak to the man? Question him as to the reason of his persistent shadowing?’

‘No, I didn’t.’ The actor hesitated. ‘I thought of doing so once or twice, but I always decided against it. It seemed to me that I should merely put the fellow on his guard and learn nothing. Possibly once they had discovered that I had spotted him, they would have put someone else on my track – someone whom I might not recognize.’

‘En effet… someone without that useful gold tooth.’

‘Exactly. I may have been wrong – but that’s how I figured it out.’

‘Now, M. Martin, you referred to “they” just now. Whom did you mean by “they”?’

‘It was a mere figure of speech used for convenience. I assumed – I don’t know why – a nebulous “they” in the background.’

‘Have you any reason for that belief?’

‘None.’ 

‘You mean you have no conception of who could want you shadowed or for what purpose?’

‘Not the slightest idea. At least–’

‘Continuez,’ said Poirot encouragingly.

‘I have an idea,’ said Bryan Martin slowly. ‘It’s a mere guess on my part, mind.’

‘A guess may be very successful sometimes, Monsieur.’

‘It concerns a certain incident that took place in London about two years ago. It was a slight incident, but an inexplicable and an unforgettable one. I’ve often wondered and puzzled over it. Just because I could find no explanation of it at the time, I am inclined to wonder if this shadowing business might not be connected in some way with it – but for the life of me I can’t see why or how.’

‘Perhaps I can.’

‘Yes, but you see–’ Bryan Martin’s embarrassment returned. ‘The awkward thing is that I can’t tell you about it – not now, that is. In a day or so I might be able to.’