"Well then, Poirot," I argued, "why did he run the risk of coming at all.
If he intended to return later for the body, I can see some point in his visit.
He would at least be removing the evidence against himself; as it is, he does not seem to have gained anything."
Poirot shrugged his most Gallic shrug.
"But you do not see with the eyes of Number Four, Hastings," he said. "You talk of evidence, but what evidence have we against him?
True, we have a body, but we have no proof even that the man was murdered - prussic acid, when inhaled, leaves no trace. Again, we can find no one who saw any one enter the flat during our absence, and we have found out nothing about the movements of our late friend, Mayerling... "No, Hastings, Number Four has left no trace, and he knows it.
His visit we may call a reconnaissance.
Perhaps he wanted to make quite sure that Mayerling was dead, but more likely, I think, he came to see Hercule Poirot, and to have speech with the adversary whom alone he must fear."
Poirot's reasoning appeared to me typically egotistical, but I forbore to argue.
"And what about the inquest?" I asked. "I suppose you will explain things clearly there, and let the police have a full description of Number Four."
"And to what end?
Can we produce anything to impress a coroner's jury of your solid Britishers?
Is our description of Number Four of any value? No; we shall allow them to call it
'Accidental Death,' and maybe, although I have not much hope, our clever murderer will pat himself on the back that he deceived Hercule Poirot in the first round."
Poirot was right as usual.
We saw no more of the man from the asylum, and the inquest, at which I gave evidence, but which Poirot did not even attend, aroused no public interest.
As, in view of his intended trip to South America, Poirot had wound up his affairs before my arrival, he had at this time no cases on hand, but although he spent most of his time in the flat I could get little out of him.
He remained buried in an arm-chair, and discouraged my attempts at conversation.
And then one morning, about a week after the murder, he asked me if I would care to accompany him on a visit he wished to make.
I was pleased, for I felt he was making a mistake in trying to work things out so entirely on his own, and I wished to discuss the case with him.
But I found he was not communicative.
Even when I asked where we were going, he would not answer.
Poirot loves being mysterious.
He will never part with a piece of information until the last possible moment.
In this instance, having taken successively a bus and two trains, and arrived in the neighbourhood of one of London's most depressing southern suburbs, he consented at last to explain matters.
"We go, Hastings, to see the one man in England who knows most of the underground life of China."
"Indeed!
Who is he?"
"A man you have never heard of - a Mr. John Ingles.
To all intents and purposes, he is a retired Civil Servant of mediocre intellect, with a house full of Chinese curios with which he bores his friends and acquaintances.
Nevertheless, I am assured by those who should know that the only man capable of giving me the information I seek is this same John Ingles."
A few moments more saw us ascending the steps of The Laurels, as Mr. Ingles's residence was called.
Personally, I did not notice a laurel bush of any kind, so deduced that it had been named according to the usual obscure nomenclature of the suburbs.
We were admitted by an impassive-faced Chinese servant and ushered into the presence of his master.
Mr. Ingles was a squarely-built man, somewhat yellow of countenance, with deep-set eyes that were oddly reflective in character.
He rose to greet us, setting aside an open letter which he had held in his hand.
He referred to it after his greeting.
"Sit down, won't you?
Halsey tells me that you want some information and that I may be useful to you in the matter."
"That is so, monsieur.
I ask of you if you have any knowledge of a man named Li Chang Yen?"
"That's rum - very rum indeed.
How did you come to hear about the man?"
"You know him, then?"
"I've met him once.
And I know something of him - not quite as much as I should like to.
But it surprises me that any one else in England should even have heard of him.
He's a great man in his way - mandarin class and all that, you know - but that's not the crux of the matter.
There's good reason to suppose that he's the man behind it all."
"Behind what?"