"Then Raymond Boynton was definitely the last person to see his mother alive?" said Poirot.

Dr. Gerard and Colonel Carbury interchanged a quick glance. Colonel Carbury drummed on the table with his fingers.

"This is where we begin to get into deep waters," he said. "Go on, Gerard. This is your pigeon."

Dr. Gerard said: "As I mentioned just now, Sarah King, when she examined Mrs. Boynton, saw no reason for determining the exact time of death. She merely said that Mrs. Boynton had been dead 'some little time'; but when, on the following day for reasons of my own, I endeavored to narrow things down and happened to mention that Mrs. Boynton was last seen alive by her son, Raymond, at a little before six, Miss King, to my great surprise, said point blank that that was impossible, that at that time Mrs. Boynton must already have been dead."

Poirot's eyebrows rose. "Odd. Extremely odd. And what does M. Raymond Boynton say to that?"

Colonel Carbury said abruptly: "He swears that his mother was alive. He went up to her and said: 'I'm back. Hope you have had a nice afternoon?' Something of that kind. He says she just grunted 'Quite all right,' and he went on to his tent."

Poirot frowned perplexedly. "Curious," he said. "Extremely curious. Tell me-it was growing dusk by then?"

"The sun was just setting."

"Curious," said Poirot again. "And you, Dr. Gerard, when did you see the body?"

"Not until the following day. At nine A.M., to be precise."

"And your estimate of the time death had occurred?"

The Frenchman shrugged his shoulders. "It is difficult to be exact after that length of time. There must necessarily be a margin of several hours. Were I giving evidence on oath I could only say that she had been dead certainly twelve hours and not longer than eighteen. You see, that does not help at all!"

"Go on, Gerard," said Colonel Carbury. "Give him the rest of it."

"On getting up in the morning," said Dr. Gerard, "I found my hypodermic syringe-it was behind a case of bottles on my dressing table." He leaned forward. "You may say, if you like, that I had overlooked it the day before. I was in a miserable state of fever and wretchedness, shaking from head to foot, and how often does one look for a thing that is there all the time and yet be unable to find it! I can only say that I am quite positive the syringe was not there then."

"There's something more still," said Carburv. "Yes, two facts for what they are worth and they mean a great deal. There was a mark on the dead woman's wrist-a mark such as would be caused by the insertion of a hypodermic syringe. Her daughter explains it as having been caused by the prick of a pin-"

Poirot stirred. "Which daughter?"

"Her daughter, Carol."

"Yes, continue, I pray you."

"And there is the last fact. Happening to examine my little case of drugs I noticed that my stock of digitoxin was very much diminished."

"Digitoxin," said Poirot, "is a heart poison, is it not?"

"Yes. It is obtained from digitalis purpurea-the common foxglove. There are four active principles-digitalin-digitonin-digitalein-and digitoxin. Of these, digitoxin is considered the most active poisonous constituent of digitalis leaves. According to Kopp's experiments, it is from six to ten times stronger than digitalin or digitalein. It is official in France-but not in the British Pharmacopoeia."

"And a large dose of digitoxin?"

Dr. Gerard said gravely: "A large dose of digitoxin thrown suddenly on the circulation by intravenous injection would cause sudden death by quick palsy of the heart. It has been estimated that four milligrams might prove fatal to an adult man."

"And Mrs. Boynton already suffered with heart trouble?"

"Yes; as a matter of fact, she was actually taking a medicine containing digitalis."

"That," said Poirot, "is extremely interesting."

"D'you mean," asked Colonel Carbury, "that her death might have been attributed to an overdose of her own medicine?"

"That-yes. But I meant more than that. In some senses," said Dr. Gerard, "digitalis may be considered a cumulative drug. Moreover, as regards postmortem appearance, the active principles of the digitalis may destroy life and leave no appreciative sign."

Poirot nodded slow appreciation. "Yes, that is clever-very clever. Almost impossible to prove satisfactorily to a jury. Ah, but let me tell you, gentlemen, if this is a murder, it is a very clever murder! The hypodermic replaced, the poison employed being one which the victim was already taking-the possibilities of a mistake-or accident-are overwhelming. Oh, yes, there are brains here. There is thought-care-genius."

For a moment he sat in silence, then he raised his head. "And yet, one thing puzzles me."

"What is that?"

"The theft of the hypodermic syringe."

"It was taken," said Dr. Gerard quickly.

"Taken-and returned?"

"Yes."

"Odd," said Poirot. "Very odd. Otherwise everything fits so well…"

Colonel Carbury looked at him curiously. "Well?" he said. "What's your expert opinion? Was it murder-or wasn't it?"

Poirot held up a hand. "One moment. We have not yet arrived at that point. There is still some evidence to consider."

"What evidence? You've had it all."

"Ah! But this is evidence that I, Hercule Poirot, bring to you." He nodded his head and smiled a little at their two astonished faces. ''Yes it is droll, that! That I, to whom you tell the story, should in return present you with a piece of evidence about which you do not know. It was like this. In the Solomon Hotel, one night, I go to the window to make sure it is closed-"

"Closed-or open?" asked Carbury.

"Closed," said Poirot firmly. "It was open, so naturally, I go to close it. But before I do so, as my hand is on the latch, I hear a voice speaking-an agreeable voice, low and clear with a tremor in it of nervous excitement. I say to myself it is a voice I will know again. And what does it say, this voice? It says these words: 'You do see, don't you, that she's got to be killed?'"

He paused.

"At the moment, naturellement, I do not take those words as referring to a killing of flesh and blood. I think it is an author or perhaps a playwright who speaks. But now I am not so sure. That is to say, I am sure it was nothing of the kind."

Again he paused before saying: "Messieurs, I will tell you this-to the best of my knowledge and belief those words were spoken by a young man whom I saw later in the lounge of the hotel and who was, so they told me on inquiring, a young man of the name of Raymond Boynton."

"RAYMOND BOYNTON SAID THAT?" The exclamation broke from the Frenchman.

"You think it unlikely-psychologically speaking?" Poirot inquired placidly.

Gerard shook his head. "No, I should not say that. I was surprised, yes. If you follow me, I was surprised just because Raymond Boynton was so eminently fitted to be a suspect."

Colonel Carbury sighed. "These psychological fellers!" the sigh seemed to say. "Question is," he murmured, "what are we going to do about it?"

Gerard shrugged his shoulders. "I do not see what you can do," he confessed. "The evidence is bound to be inconclusive. You may know that murder has been done but it will be difficult to prove it."

"I see," said Colonel Carbury. "We suspect that murder's been done and we just sit back and twiddle our fingers! Don't like it!" He added, as if in extenuation, his former odd plea: "I'm a tidy man."

"I know. I know," Poirot nodded his head sympathetically. "You would like to clear this up. You would like to know definitely exactly what occurred and how it occurred. And you. Dr. Gerard? You have said that there is nothing to be done-that the evidence is bound to be inconclusive? That is probably true. But are you satisfied that the matter should rest so?"

"She was a bad life," said Gerard slowly. "In any case she might have died very shortly-a week-a month-a year."

"So you are satisfied?" persisted Poirot.

Gerard went on: "There is no doubt that her death was-how shall we put it?-beneficial to the community. It has brought freedom to her family. They will have scope to develop-they are all, I think, people of good character and intelligence. They will be, now, useful members of society! The death of Mrs. Boynton, as I see it, has resulted in nothing but good."

Poirot repeated for the third time: "So you are satisfied?"

"No." Dr. Gerard pounded a fist suddenly on the table. "I am not 'satisfied,' as you put it! It is my instinct to preserve life-not to hasten death. Therefore, though my conscious mind may repeat that this woman's death was a good thing, my unconscious mind rebels against it! It is not well, gentlemen, that a human being should die before his or her time has come."

Poirot smiled. He leaned back, contented with the answer he had probed for so patiently.

Colonel Carbury said unemotionally: "He don't like murder! Quite right! No more do I." He rose and poured himself out a stiff whisky and soda. His guests' glasses were still full. "And now," he said, returning to the subject, "let's get down to brass tacks. Is there anything to be done about it? We don't like it-no! But we may have to lump it! No good making a fuss if you can't deliver the goods."

Gerard leaned forward. "What is your professional opinion, M. Poirot? You are the expert."

Poirot took a little time to speak. Methodically he arranged an ashtray or two and made a little heap of used matches. Then he said: "You desire to know, do you not, Colonel Carbury, who killed Mrs. Boynton? (That is, if she was killed and did not die a natural death.) Exactly how and when she was killed-and, in fact, the whole truth of the matter?"

"I should like to know that, yes." Carbury spoke unemotionally.

Hercule Poirot said slowly: "I see no reason why you should not know it!"

Dr. Gerard looked incredulous. Colonel Carbury looked mildly interested. "Oh," he said. "So you don't, don't you? That's interestin'. How d'you propose to set about it?"