“After that Dr. and Mrs. Leidner go abroad and for eighteen months they lead a happy, peaceful life with no threats of death to disturb it. They put that down to having successfully covered their traces, but such an explanation is quite absurd. In these days going abroad is quite inadequate for that purpose. And especially was that so in the case of the Leidners. He was the director of a museum expedition. By inquiry at the museum, Frederick Bosner could at once have obtained his correct address. Even granting that he was in too reduced circumstances to pursue the couple himself there would be no bar to his continuing his threatening letters. And it seems to me that a man with his obsession would certainly have done so.
“Instead nothing is heard of him until nearly two years later when the letters are resumed.
“Why were the letters resumed?
“A very difficult question—most easily answered by saying that Mrs. Leidner was bored and wanted more drama. But I was not quite satisfied with that. This particular form of drama seemed to me a shade too vulgar and too crude to accord well with her fastidious personality.
“The only thing to do was to keep an open mind on the question.
“There were three definite possibilities: (1) the letters were written by Mrs. Leidner herself; (2) they were written by Frederick Bosner (or young William Bosner); (3) they might have been written originally by either Mrs. Leidner or her first husband, but they were now forgeries—that is, they were being written by a third person who was aware of the earlier letters.
“I now come to direct consideration of Mrs. Leidner’s entourage.
“I examined first the actual opportunities that each member of the staff had had for committing the murder.
“Roughly, on the face of it, anyone might have committed it (as far as opportunity went), with the exception of three persons.
“Dr. Leidner, by overwhelming testimony, had never left the roof. Mr. Carey was on duty at the mound. Mr. Coleman was in Hassanieh.
“But those alibis, my friends, were not quite as good as they looked. I except Dr. Leidner’s. There is absolutely no doubt that he was on the roof all the time and did not come down until quite an hour and a quarter after the murder had happened.
“But was it quite certain that Mr. Carey was on the mound all the time?
“And had Mr. Coleman actually been in Hassanieh at the time the murder took place?”
Bill Coleman reddened, opened his mouth, shut it and looked round uneasily.
Mr. Carey’s expression did not change.
Poirot went on smoothly.
“I also considered one other person who, I satisfied myself, would be perfectly capable of committing murder if she felt strongly enough. Miss Reilly has courage and brains and a certain quality of ruthlessness. When Miss Reilly was speaking to me on the subject of the dead woman, I said to her, jokingly, that I hoped she had an alibi. I think Miss Reilly was conscious then that she had had in her heart the desire, at least, to kill. At any rate she immediately uttered a very silly and purposeless lie. She said she had been playing tennis on that afternoon. The next day I learned from a casual conversation with Miss Johnson that far from playing tennis, Miss Reilly had actually been near this house at the time of the murder. It occurred to me that Miss Reilly, if not guilty of the crime, might be able to tell me something useful.”
He stopped and then said quietly: “Will you tell us, Miss Reilly, what you did see that afternoon?”
The girl did not answer at once. She still looked out of the window without turning her head, and when she spoke it was in a detached and measured voice.
“I rode out to the dig after lunch. It must have been about a quarter to two when I got there.”
“Did you find any of your friends on the dig?”
“No, there seemed to be no one there but the Arab foreman.”
“You did not see Mr. Carey?”
“No.”
“Curious,” said Poirot. “No more did M. Verrier when he went there that same afternoon.”
He looked invitingly at Carey, but the latter neither moved nor spoke.
“Have you any explanation, Mr. Carey?”
“I went for a walk. There was nothing of interest turn-
ing up.”
“In which direction did you go for a walk?”