"No one would think of looking there," Poirot continued."And he will be able, at his leisure, to come back and destroy this solitary piece of evidence against him.""Then, all the time, it was in the spill vase in Mrs.Inglethorp's bedroom, under our very noses?" I cried.
Poirot nodded.
"Yes, my friend.That is where I discovered my 'last link,' and I owe that very fortunate discovery to you.""To me?"
"Yes.Do you remember telling me that my hand shook as I was straightening the ornaments on the mantel-piece?""Yes, but I don't see--"
"No, but I saw.Do you know, my friend, I remembered that earlier in the morning, when we had been there together, I had straightened all the objects on the mantel-piece. And, if they were already straightened, therewould be no need to straighten them again, unless, in the meantime, some one else had touched them.""Dear me," I murmured, "so that is the explanation of your extraordinary behaviour.You rushed down to Styles, and found it still there?""Yes, and it was a race for time."
"But I still can't understand why Inglethorp was such a fool as to leave it there when he had plenty of opportunity to destroy it.""Ah, but he had no opportunity.I saw to that." "You?""Yes.Do you remember reproving me for taking the household into my confidence on the subject?""Yes."
"Well, my friend, I saw there was just one chance.I was not sure then if Inglethorp was the criminal or not, but if he was I reasoned that he would not have the paper on him, but would have hidden it somewhere, and by enlisting the sympathy of the household I could effectually prevent his destroying it.He was already under suspicion, and by making 190> the matter public I secured the services of about ten amateur detectives, who would be watching him unceasingly, and being himself aware of their watchfulness he would not dare seek further to destroy the document.He was therefore forced to depart from the house, leaving it in the spill vase.""But surely Miss Howard had ample opportunities of aiding him." "Yes, but Miss Howard did not know of the paper's existence.Inaccordance with their prearranged plan, she never spoke to Alfred Inglethorp.They were supposed to be deadly enemies, and until John Cavendish was safely convicted they neither of them dared risk a meeting.Of course I had a watch kept on Mr.Inglethorp, hoping that sooner or later he would lead me to the hiding-place.But he was too clever to take any chances.The paper was safe where it was; since no one had thought of looking there in the first week, it was not likely they would do so afterwards.But for your lucky remark, we might never have been able to bring him to justice.""I understand that now; but when did you first begin to suspect Miss Howard?""When I discovered that she had told a lie at the inquest about the letter she had received from Mrs.Inglethorp.""Why, what was there to lie about?"
"You saw that letter? Do you recall its general appearance?" "Yes--more or less.""You will recollect, then, that Mrs.Inglethorp wrote a very distinctive hand, and left large clear spaces between her words.But if you look at the date at the top of the letter you will notice that 'July 17th' is quite different in this respect. Do you see what I mean?""No," I confessed, "I don't."
"You do not see that that letter was not written on the 17th, but on the 7th--the day after Miss Howard's departure? The '1' was written in before the '7' to turn it into the '17th'.""But why?"
"That is exactly what I asked myself.Why does Miss Howard suppress the letter written on the 17th, and produce this faked one instead? Because she did not wish to show the letter of the 17th.Why, again? And at once a suspicion dawned in my mind.You will remember my saying that it was wise to beware of people who were not telling you the truth.""And yet," I cried indignantly, "after that, you gave me two reasons why Miss Howard could not have committed the crime!""And very good reasons too," replied Poirot."For a long time they were a stumbling-block to me until I remembered a very significant fact: that she and Alfred Inglethorp were cousins.She could not have committed the crime single-handed, but the reasons against that did not debar her from being an accomplice.And, then, there was that rather over-vehement hatred of hers! It concealed a very opposite emotion.There was, undoubtedly, a tie of passion between them long before he came to Styles.They had already arranged their infamous plot--that he should marry this rich, but rather foolish old lady, induce her to make a will leaving her money to him, and then gain their ends by a very cleverlyconceived crime.If all had gone as they planned, they would probably have left England, and lived together on their poor victim's money.
