accompanied her. The three men had adjourned to M. Deroulard's study. Here they had chatted amicably for some time, when suddenly, without any warning, the deputy had fallen heavily to the ground. M. de Saint Alard had rushed out and told Francois to fetch a doctor immediately. He said it was without doubt an apoplexy, explained the man. But when the doctor arrived, the patient was past help.
Mr John Wilson, to whom I was presented by Mademoiselle Virginie, was what was known in those days as a regular John Bull Englishman, middle-aged and burly. His account, delivered in very British French, was substantially the same.
'Deroulard went very red in the face, and down he fell.'
There was nothing further to be found out there. Next I went to the scene of the tragedy, the study, and was left alone there at my own request. So far there was nothing to support Mademoiselle Mesnard's theory. I could not but believe that it was a delusion on her part. Evidently she had entertained a romantic passion for the dead man which had not permitted her to take a normal view of the case. Nevertheless, I searched the study with meticulous care. It was just possible that a hypodermic needle might have been introduced into the dead man's chair in such a way as to allow of a fatal injection. The minute puncture it would cause was likely to remain unnoticed. But I could discover no sign to support that theory. I flung myself down in the chair with a gesture of despair.
'Enfin, I abandon it!' I said aloud. 'There is not a clue anywhere! Everything is perfectly normal.'
As I said the words, my eyes fell on a large box of chocolates standing on a table near by, and my heart gave a leap. It might not be a clue to M. Deroulard's death, but here at least was something that was not normal. I lifted the lid. The box was full, untouched; not a chocolate was missing – but that only made the peculiarity that had caught my eye more striking. For, see you, Hastings, while the box itself was pink, the lid was blue. Now, one often sees a blue ribbon on a pink box, and vice versa, but a box of one colour, and a lid of another – no; decidedly – ca ne se voit jamais!
I did not as yet see that this little incident was of any use to me, yet I determined to investigate it as being out of the ordinary. I rang the bell for Francois, and asked him if his late master had been fond of sweets. A faint melancholy smile came to his lips.
'Passionately fond of them, monsieur. He would always have a box of chocolates in the house. He did not drink wine of any kind, you see.'
'Yet this box has not been touched?' I lifted the lid to show him.
'Pardon, monsieur, but that was a new box purchased on the day of his death, the other being nearly finished.'
'Then the other box was finished on the day of his death,' I said slowly.
'Yes, monsieur, I found it empty in the morning and threw it away.'
'Did M. Deroulard eat sweets at all hours of the day?'
'Usually after dinner, monsieur.'
I began to see light.
'Francois,' I said, 'you can be discreet?'
'If there is need, monsieur.'
'Bon! Know, then, that I am of the police. Can you find me that other box?'
'Without doubt, monsieur. It will be in the dustbin.'
He departed, and returned in a few minutes with a dust-covered object. It was the duplicate of the box I held, save for the fact that this time the box was blue and the lid was pink. I thanked Francois, recommended him once more to be discreet, and left the house in the Avenue Louise without more ado.
Next day I called upon the doctor who had attended M. Deroulard. With him I had a difficult task. He entrenched himself prettily behind a wall of learned phraseology, but I fancied that he was not quite as sure about the case as he would like to be.
'There have been many curious occurrences of the kind,' he observed, when I had managed to disarm him somewhat. 'A sudden fit of anger, a violent emotion – after a heavy dinner, c'est entendu – then, with an access of rage, the blood flies to the head, and pst! – there you are!'
'But M. Deroulard had had no violent emotion.'
'No? I made sure that he had been having a stormy altercation with M. de Saint Alard.'
'Why should he?'
'C'est evident!' The doctor shrugged his shoulders. 'Was not M. de Saint Alard a Catholic of the most fanatical? Their friendship was being ruined by this question of church and state. Not a day passed without discussions. To M. de Saint Alard, Deroulard appeared almost as Antichrist.'
This was unexpected, and gave me food for thought.
'One more question, Doctor: would it be possible to introduce a fatal dose of poison into a chocolate?'
'It would be possible, I suppose,' said the doctor slowly. 'Pure prussic acid would meet the case if there were no chance of evaporation, and a tiny globule of anything might be swallowed unnoticed – but it does not seem a very likely supposition. A chocolate full of morphine or strychnine -' He made a wry face. 'You comprehend, M. Poirot – one bite would be enough! The unwary one would not stand upon ceremony.'
'Thank you, M. le Docteur.'
I withdrew. Next I made enquiries of the chemists, especially those in the neighbourhood of the Avenue Louise. It is good to be of the police. I got the information I wanted without any trouble. Only in one case could I hear of any poison having been supplied to the house in question. This was some eye drops of atropine sulphate for Madame Deroulard. Atropine is a potent poison, and for the moment I was elated, but the symptoms of atropine poisoning are closely allied to those of ptomaine, and bear no resemblance to those I was studying. Besides, the prescription was an old one. Madame Deroulard had suffered from cataract in both eyes for many years.
I was turning away discouraged when the chemist's voice called me back.
'Un moment, M. Poirot. I remember, the girl who brought that prescription, she said something about having to go on to the English chemist. You might try there.'
I did. Once more enforcing my official status, I got the information I wanted. On the day before M. Deroulard's death they had made up a prescription for Mr John Wilson. Not that there was any making up about it. They were simply little tablets of trinitrine. I asked if I might see some. He showed me them, and my heart beat faster – for the tiny tablets were of chocolate.
'It is a poison?' I asked.
'No, monsieur.'
'Can you describe to me its effect?'
'It lowers the blood-pressure. It is given for some forms of heart trouble – angina pectoris for instance. It relieves the arterial tension. In arteriosclerosis -'
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 held the means for the crime – but what about the motive? He had come to Belgium on business, and had asked M. Deroulard, whom he knew slightly, to put him up. There was apparently no way in which Deroulard's death could benefit him. Moreover, I discovered by enquiries 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 trinitrin 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
