“Why did you measure that overcoat?” I asked, with some curiosity, as we walked down the hot white road at a pace.  
“Parbleu! to see how long it was,” replied my friend .
 
I was . Poirot’s habit of making a mystery out of nothing never failed to irritate me. I relapsed into silence, and followed a train of thought of my own. Although I had not noticed them at the time, certain words Mrs. Renauld had addressed to her son now to me, with a new significance. “So you did not sail?” she had said, and then had added: “After all, it does not matter—now.”
 
What had she meant by that? The words were enigmatical—significant. Was it possible that she knew more than we supposed? She had denied all knowledge of the mysterious mission with which her husband was to have his son. But was she really less ignorant than she pretended? Could she enlighten us if she chose, and was her silence part of a carefully thought out and preconceived plan?
 
The more I thought about it, the more I was convinced that I was right. Mrs. Renauld knew more than she chose to tell. In her surprise at seeing her son, she had momentarily betrayed herself. I felt convinced that she knew, if not the assassins, at least the for the . But some very powerful considerations must keep her silent.
 
“You think profoundly, my friend,” remarked Poirot, breaking in upon my reflections. “What is it that you so?”
 
I told him, sure of my ground, though feeling expectant that he would my suspicions. But to my surprise he nodded thoughtfully.
 
“You are quite right, Hastings. From the beginning I have been sure that she was keeping something back. At first I suspected her, if not of inspiring, at least of at the crime.”
 
“You suspected her?” I cried.
 
“But certainly! She benefits enormously—in fact, by this new will, she is the only person to benefit. So, from the start, she was singled out for attention. You may have noticed that I took an early opportunity of examining her wrists. I wished to see whether there was any possibility that she had gagged and bound herself. Eh bien, I saw at once that there was no fake, the cords had actually been so tight as to cut into the flesh. That ruled out the possibility of her having committed the crime single-handed. But it was still possible for her to have at it, or to have been the with an . Moreover, the story, as she told it, was singularly familiar to me—the masked men that she could not recognize, the mention of ‘the secret’—I had heard, or read, all these things before. Another little detail confirmed my belief that she was not speaking the truth. The wrist watch, Hastings, the wrist watch!”
 
Again that wrist watch! Poirot was eyeing me .
 
“You see, mon ami? You comprehend?”
 
“No,” I replied with some ill humour. “I neither see nor comprehend. You make all these confounded mysteries, and it’s useless asking you to explain. You always like keeping everything up your sleeve to the last minute.”
 
“Do not yourself, my friend,” said Poirot with a smile. “I will explain if you wish. But not a word to Giraud, c’est entendu? He treats me as an old one of no importance! We shall see! In common fairness I gave him a hint. If he does not choose to act upon it, that is his own look out.”
 
I assured Poirot that he could rely upon my .
 
“C’est bien! Let us then employ our little grey cells. Tell me, my friend, at what time, according to you, did the tragedy take place?”
 
“Why, at two o’clock or thereabouts,” I said, astonished. “You remember, Mrs. Renauld told us that she heard the clock strike while the men were in the room.”
 
“Exactly, and on the strength of that, you, the examining , Bex, and every one else, accept the time without further question. But I, Hercule Poirot, say that Madame Renauld lied. The crime took place at least two hours earlier.”
 
“But the doctors—”
 
“They declared, after examination of the body, that death had taken place between ten and seven hours . Mon ami, for some reason, it was that the crime should seem to have taken place later than it actually did. You have read of a smashed watch or clock the exact hour of a crime? So that the time should not rest on Mrs. Renauld’s alone, some one moved on the hands of that wrist watch to two o’clock, and then dashed it violently to the ground. But, as is often the case, they defeated their own object. The glass was smashed, but the of the watch was uninjured. It was a most on their part, for it at once drew my attention to two points—first, that Madame Renauld was lying: , that there must be some vital reason for the of the time.”
 
“But what reason could there be?”
 
“Ah, that is the question! There we have the whole mystery. As yet, I cannot explain it. There is only one idea that presents itself to me as having a possible connection.”
 
“And that is?”
 
“The last train left Merlinville at seventeen minutes past twelve.”
 
I followed it out slowly.
 
“So that, the crime taking place some two hours later, any one leaving by that train would have an !”
 
“Perfect, Hastings! You have it!”
 
I sprang up.
 
“But we must inquire at the station. Surely they cannot have failed to notice two foreigners who left by that train! We must go there at once!”
 
“You think so, Hastings?”
 
“Of course. Let us go there now.”
 
Poirot restrained my ardour with a light touch upon the arm.
 
“Go by all means if you wish, mon ami—but if you go, I should not ask for particulars of two foreigners.”
 
I stared, and he said rather impatiently:
 
“Là, là, you do not believe all that rigmarole, do you? The masked men and all the rest of cette histoire-là!”
 
His words took me so much aback that I hardly knew how to respond. He went on :
 
“You heard me say to Giraud, did you not, that all the details of this crime were familiar to me? Eh bien, that presupposes one of two things, either the brain that planned the first crime also planned this one, or else an account read of a cause célèbre unconsciously remained in our assassin’s memory and prompted the details. I shall be able to pronounce definitely on that after—” he broke off.
 
I was matters in my mind.
 
“But Mr. Renauld’s letter? It distinctly mentions a secret and Santiago?”
 
“Undoubtedly there was a secret in M. Renauld’s life—there can be no doubt of that. On the other hand, the word Santiago, to my mind, is a red herring, dragged continually across the track to put us off the . It is possible that it was used in the same way on M. Renauld, to keep him from directing his suspicions into a quarter nearer at hand. Oh, be assured, Hastings, the danger that threatened him was not in Santiago, it was near at hand, in France.”
 
He so gravely, and with such assurance, that I could not fail to be convinced. But I essayed one final objection:
 
“And the match and cigarette end found near the body............