Poirot was silent for a moment, then he said: "There is a fact, Miss King, that you do not yet know. Dr. Gerard has not told you of it."

"What fact?" demanded Sarah.

"A supply of a drug—digitoxin—is missing from Dr. Gerard's traveling medicine case."

"Oh!" Quickly Sarah took in this new aspect of the case. Equally quickly she pounced on the one doubtful point. "Is Dr. Gerard quite sure of that?"

Poirot shrugged his shoulders. "A doctor, as you should know, Mademoiselle, is usually fairly careful in making his statements."

"Oh, of course. That goes without saying. But Dr. Gerard had malaria at the time."

"That is so, of course."

"Has he any idea when it could have been taken?"

"He had occasion to go to his case on the night of his arrival in Petra. He wanted some phenacetin as his head was aching badly. When he replaced the phenacetin on the following morning and shut up the case he is almost certain that all the drugs were intact."

"Almost—" said Sarah.

Poirot shrugged.

"Yes, there is a doubt! There is the doubt that any man, who is honest, would be likely to feel."

Sarah nodded. "Yes, I know. One always distrusts those people who are over-sure. But all the same, M. Poirot, the evidence is very slight. It seems to me—" She paused.

Poirot finished the sentence for her. "It seems to you that an inquiry on my part is ill-advised!"

Sarah looked him squarely in the face. "Frankly, it does. Are you sure, M. Poirot, that this is not a case of Roman Holiday?"

Poirot smiled. "The private lives of a family upset and disturbed—so that Hercule Poirot can play a little game of detection to amuse himself?"

"I didn't mean to be offensive—but isn't it a little like that?"

"You, then, are on the side of the famille Boynton, Mademoiselle?"

"I think I am. They've suffered a good deal. They—they oughtn't to have to stand any more."

"And la Maman, she was unpleasant, tyrannical, disagreeable and decidedly better dead than alive? That also—hm?"

"When you put it like that—" Sarah paused, flushed, went on: "One shouldn't, I agree, take that into consideration."

"But all the same one does! That is, you do. Mademoiselle! I do not! To me, it is all the same. The victim may be one of the good God's saints—or, on the contrary, a monster of infamy. It moves me not. The fact is the same. A life taken! I say it always, I do not approve of murder."

"Murder!" Sarah drew in her breath sharply. "But what evidence of that is there? The flimsiest imaginable! Dr. Gerard himself cannot be sure!"

Poirot said quietly: "But there is other evidence, Mademoiselle."

"What evidence?" Her voice was sharp.

"The mark of a hypodermic puncture upon the dead woman's wrist. And something more still—some words that I overheard spoken in Jerusalem on a clear still night when I went to close my bedroom window. Shall I tell you what those words were, Miss King? They were these: I heard Mr. Raymond Boynton say: 'You do see, don't you, that she's got to be killed?'" He saw the color drain slowly from Sarah's face.