"Now, from that new standpoint, let us consider the events of the afternoon! The Boynton family goes off. Mrs. Boynton sits up by her cave. Now, let us consider very carefully the evidence of Lady Westholme and Miss Pierce. The latter is an unreliable witness, she is unobservant and very suggestible. Lady Westholme, on the other hand, is perfectly clear as to her facts and meticulously observant. Both ladies agree on one fact! An Arab, one of the servants, approaches Mrs. Boynton, angers her in some way and retires hastily. Lady Westholme states definitely that the servant had first been into the tent occupied by Ginevra Boynton but you may remember that Dr. Gerard's tent was next door to Ginevra's. It is possible that it was Dr. Gerard's tent the Arab entered. . . ."

Colonel Carbury said: "D'you mean to tell me that one of those Bedouin fellows of mine murdered an old lady by sticking her with a hypodermic? Fantastic!"

"Wait, Colonel Carbury; I have not yet finished. Let us agree that the Arab might have come from Dr. Gerard's tent and not Ginevra Boynton's. What is the next thing? Both ladies agree that they could not see his face clearly enough to identify him and that they did not hear what was said. That is understandable. The distance between the marquee and the ledge is about two hundred yards. Lady Westholme gave a clear description of the man otherwise, describing in detail his ragged breeches and the untidiness with which his puttees were rolled."

Poirot leaned forward. "And that, my friends, was very odd indeed! Because, if she could not see his face or hear what was said, she could not possibly have noticed the state of his breeches and puttees! Not at two hundred yards!"

"It was an error, that, you see! It suggested a curious idea to me. Why insist so on the ragged breeches and untidy puttees. Could it be because the breeches were not torn and the puttees were non-existent? Lady Westholme and Miss Pierce both saw the man—but from where they were sitting they could not see each other. That is shown by the fact that Lady Westholme came to see if Miss Pierce was awake and found her sitting in the entrance of her tent."

"Good Lord," said Colonel Carbury, suddenly sitting up very straight. "Are you suggesting—"

"I am suggesting that having ascertained just what Miss Pierce (the only witness likely to be awake) was doing, Lady Westholme returned to her tent, put on her riding breeches, boots and khaki-colored coat, made herself an Arab headdress with her checked duster and a skein of knitting wool and that, thus attired, she went boldly up to Dr. Gerard's tent, looked in his medicine chest, selected a suitable drug, took the hypodermic, filled it and went boldly up to her victim."

"Mrs. Boynton may have been dozing. Lady Westholme was quick. She caught her by the wrist and injected the stuff. Mrs. Boynton half cried out—tried to rise—then sank back. The 'Arab' hurried away with every evidence of being ashamed and abashed. Mrs. Boynton shook her stick, tried to rise, then fell back into her chair."