Dear M. Poirot,—I was much touched by your kind—your very kind letter. I have been feeling so bewildered by everything. Apart from my terrible grief, I have been so affronted by the things that seem to have been hinted about Carlotta—the dearest, sweetest sister that a girl ever had. No, M. Poirot, she did not take drugs. I’m sure of it. She had a horror of that kind of thing. I’ve often heard her say so. If she played a part in that poor man’s death, it was an entirely innocent one—but of course her letter to me proves that. I am sending you the actual letter itself since you ask me to do so. I hate parting with the last letter she ever wrote, but I know you will take care of it and let me have it back, and if it helps you to clear up some of the mystery about her death, as you say it may do—why, then, of course it must go to you.
You ask whether Carlotta mentioned any friend specially in her letters. She mentioned a great many people, of course, but nobody in a very outstanding way. Bryan Martin whom we used to know years ago, a girl called Jenny Driver, and a Captain Ronald Marsh were, I think, the ones she saw most of.
I wish I could think of something to help you. You write so kindly and with such understanding, and you seem to realize what Carlotta and I were to each other.
Gratefully yours,
Lucie Adams
P.S. An officer has just been here for the letter. I told him that I had already mailed it to you. This, of course, was not true, but I felt somehow or other that it was important you should see it first. It seems Scotland Yard need it as evidence, against the murderer. You will take it to them. But, oh! please be sure they let you have it back again some day. You see, it is Carlotta’s last words to me.
‘So you wrote yourself to her,’ I remarked as I laid the letter down. ‘Why did you do that, Poirot? And why did you ask for the original of Carlotta Adams’ letter?’
He was bending over the enclosed sheets of the letter I mentioned.
‘In verity I could not say, Hastings—unless it is that I hoped against hope that the original letter might in some way explain the inexplicable.’
‘I don’t see how you can get away from the text of that letter. Carlotta Adams gave it herself to the maid to post. There was no hocus pocus about it. And certainly it reads as a perfectly genuine ordinary epistle.’
Poirot sighed.
‘I know. I know. And that is what makes it so difficult. Because, Hastings, as it stands, that letter is impossible.’
‘Nonsense.’
‘Si, si, it is so. See you, as I have reasoned it out, certain things must be—they follow each other with method and order in an understandable fashion. But then comes this letter. It does not accord. Who, then, is wrong? Hercule Poirot or the letter?’
‘You don’t think it possible that it could be Hercule Poirot?’ I suggested as delicately as I was able.
Poirot threw me a glance of reproof.
‘There are times when I have been in error—but this is not one of them. Clearly then, since the letter seems impossible, it is impossible. There is some fact about the letter which escapes us. I seek to discover what that fact is.’
And thereupon he resumed his study of the letter in question, using a small pocket microscope.
As he finished perusing each page, he passed it across to me. I, certainly, could find nothing amiss. It was written in a firm fairly legible handwriting and it was word for word as it had been telegraphed across.
Poirot sighed deeply.
‘There is no forgery of any kind here—no, it is all written in the same hand. And yet, since, as I say, it is impossible—’
He broke off. With an impatient gesture he demanded the sheets from me. I passed them over, and once again he went slowly through them.
Suddenly he uttered a cry.