I interrupted him. “Ma foi! This rigmarole says nothing to me. Does it cause the face to flush?”
“Certainly it does.”
“And supposing I ate ten—twenty of your little tablets, what then?”
“I should not advise you to attempt it,” he replied drily.
“And yet you say it is not poison?”
“There are many things not called poison which can kill a man,” he replied as before.
I left the shop elated. At last, things had begun to march!
I now knew that John Wilson had the means for the crime—but what about the motive? He had come to Belgium on business, and had asked M. Déroulard, whom he knew slightly, to put him up. There was apparently no way in which Déroulard’s death could benefit him. Moreover, I discovered by inquiries in England that he had suffered for some years from that painful form of heart disease known as angina. Therefore he had a genuine right to have those tablets in his possession. Nevertheless, I was convinced that someone had gone to the chocolate box, opening the full one first by mistake, and had abstracted the contents of the last chocolate, cramming in instead as many little trinitrine tablets as it would hold. The chocolates were large ones. Between twenty or thirty tablets, I felt sure, could have been inserted. But who had done this?
There were two guests in the house. John Wilson had the means. Saint Alard had the motive. Remember, he was a fanatic, and there is no fanatic like a religious fanatic. Could he, by any means, have got hold of John Wilson’s trinitrine?
Another little idea came to me. Ah, you smile at my little ideas! Why had Wilson run out of trinitrine? Surely he would bring an adequate supply from England. I called once more at the house in the Avenue Louise. Wilson was out, but I saw the girl who did his room, Félice. I demanded of her immediately whether it was not true that M. Wilson had lost a bottle from his washstand some little time ago. The girl responded eagerly. It was quite true. She, Félice, had been blamed for it. The English gentleman had evidently thought that she had broken it, and did not like to say so. Whereas she had never even touched it. Without doubt it was Jeannette—always nosing round where she had no business to be—
I calmed the flow of words, and took my leave. I knew now all that I wanted to know. It remained for me to prove my case. That, I felt, would not be easy. I might be sure that Saint Alard had removed the bottle of trinitrine from John Wilson’s washstand, but to convince others, I would have to produce evidence. And I had none to produce!
Never mind. I knew—that was the great thing. You remember our difficulty in the Styles case, Hastings? There again, I knew—but it took me a long time to find the last link which made my chain of evidence against the murderer complete.
I asked for an interview with Mademoiselle Mesnard. She came at once. I demanded of her the address of M. de Saint Alard. A look of trouble came over her face.
“Why do you want it, monsieur?”
“Mademoiselle, it is necessary.”
She seemed doubtful—troubled.
“He can tell you nothing. He is a man whose thoughts are not in this world. He hardly notices what goes on around him.”
“Possibly, mademoiselle. Nevertheless, he was an old friend of M. Déroulard’s. There may be things he can tell me—things of the past—old grudges—old love-affairs.”
The girl flushed and bit her lip. “As you please—but—but I feel sure now that I have been mistaken. It was good of you to accede to my demand, but I was upset—almost distraught at the time. I see now that there is no mystery to solve. Leave it, I beg of you, monsieur.”
I eyed her closely.
“Mademoiselle,” I said, “it is sometimes difficult for a dog to find a scent, but once he has found it, nothing on earth will make him leave it! That is if he is a good dog! And I, mademoiselle, I, Hercule Poirot, am a very good dog.”
Without a word she turned away. A few minutes later she returned with the address written on a sheet of paper. I left the house. François was waiting for me outside. He looked at me anxiously.
“There is no news, monsieur?”
“None as yet, my friend.”
“Ah! Pauvre Monsieur Déroulard!” he sighed. “I too was of his way of thinking. I do not care for priests. Not that I would say so in the house. The women are all devout—a good thing perhaps. Madame est très pieuse—et Mademoiselle Virginie aussi.”
Mademoiselle Virginie? Was she “très pieuse?” Thinking of the tear-stained passionate face I had seen that first day, I wondered.
Having obtained the address of M. de Saint Alard, I wasted no time. I arrived in the neighbourhood of his château in the Ardennes but it was some days before I could find a pretext for gaining admission to the house. In the end I did—how do you think—as a plumber, mon ami! It was the affair of a moment to arrange a neat little gas leak in his bedroom. I departed for my tools, and took care to return with them at an hour when I knew I should have the field pretty well to myself. What I was searching for, I hardly knew. The one thing needful, I could not believe there was any chance of finding. He would never have run the risk of keeping it.
Still when I found the little cupboard above the washstand locked, I could not resist the temptation of seeing what was inside it. The lock was quite a simple one to pick. The door swung open. It was full of old bottles. I took them up one by one with a trembling hand. Suddenly, I uttered a cry. Figure to yourself, my friend, I held in my hand a little phial with an English chemist’s label. On it were the words: “Trinitrine Tablets. One to be taken when required. Mr. John Wilson.”
I controlled my emotion, closed the cupboard, slipped the bottle into my pocket, and continued to repair the gas leak! One must be methodical. Then I left the château, and took train for my own country as soon as possible. I arrived in Brussels late that night. I was writing out a report for the préfet in the morning, when a note was brought to me. It was from old Madame
Déroulard, and it summoned me to the house in the Avenue Louise without delay.
François opened the door to me.
“Madame la Baronne is awaiting you.”
He conducted me to her apartments. She sat in state in a large armchair. There was no sign of Mademoiselle Virginie.
“M. Poirot,” said the old lady, “I have just learned that you are not what you pretend to be. You are a police officer.”
“That is so, madame.”
“You came here to inquire into the circumstances of my son’s death?”
Again I replied: “That is so, madame.”
“I should be glad if you would tell me what progress you have made.”
I hesitated.
“First I would like to know how you have learned all this, madame.”
“From one who is no longer of this world.”
Her words, and the brooding way she uttered them, sent a chill to my heart. I was incapable of speech.
“Therefore, monsieur, I would beg of you most urgently to tell me exactly what progress you have made in your investigation.”
“Madame, my investigation is finished.”
“My son?”
“Was killed deliberately.”
“You know by whom?”
“Yes, madame.”
“Who, then?”
“M. de Saint Alard.”
“You are wrong. M. de Saint Alard is incapable of such a crime.”
“The proofs are in my hands.”
“I beg of you once more to tell me all.”
This time I obeyed, going over each step that had led me to the discovery of the truth. She listened attentively. At the end she nodded her head.
“Yes, yes, it is all as you say, all but one thing. It was not M. de Saint Alard who killed my son. It was I, his mother.”
I stared at her. She continued to nod her head gently.
“It is well that I sent for you. It is the providence of the good God that Virginie told me before she departed for the convent, what she had done. Listen, M. Poirot! My son was an evil man. He persecuted the church. He led a life of mortal sin. He dragged down the other souls beside his own. But there was worse than that. As I came out of my room in this house one morning, I saw my daughter-in-law standing at the head of the stairs. She was reading a letter. I saw my son steal up behind her. One swift push, and she fell, striking her head on the marble steps. When they picked her up she was dead. My son was a murderer, and only I, his mother, knew it.”