"Precisely. A forgery written in triplicate."

"She wrote one to herself, too?"

"Naturally. The forgery was quite skilful--it would not deceive an expert, of course--but, then, it was highly unlikely that an expert would have been called in.

All the evidence pointed to Mrs. Lorrimer's having committed suicide."

"You will excuse my curiosity, M. Poirot, but what made you suspect that she had not committed suicide?"

"A little conversation that I had with a maidservant at Cheyne Lane."

"She told you of Anne Meredith's visit the former evening?"

"That among other things. And then, you see, I had already come to conclusion in my own mind as to the ident.i.ty of the guilty person--that is, the person who killed Mr. Shaitana. That person was not Mrs. Lorrimer."

"What made you suspect Miss Meredith?"

Poirot raised his hand.

"A little minute. Let me approach this matter in my own way. Let me, that is to say, eliminate. The murderer of Mr. Shaitana was not Mrs. Lorrimer, nor was it Major Despard, and, curiously enough, it was not Anne Meredith "

He leaned forward. His voice purred, soP and catlike.

"You see, Dr. Roberts, you were the person who killed Mr. Shaitana; and you also killed Mrs. Lorrimer .... "

There was at least three minutes' silence. Then Roberts laughed a rather menacing laugh. "Are you quite mad, M. Poirot? I certainly did not murder Mr. Shaitana, and I could not possibly have murdered Mrs. Lorrimer. My dear Battle" he turned to the Scotland Yard man "are qou standing for this?"

"I think you'd better listen to what M. Poirot has to say,' said Battle QUIETLY.

Poirot said: "It is true that though I have known for some time that you--and only you--could have killed Shaitana, it would not be an easy matter to prove it. But MrS.

Lorrimer's case is quite different." He leaned forward. "It is not a case of my knowing. It is much simpler than that for we have an eye-witness who saw you do.

it."

Roberts grew very quiet. His eyes glittered. He said sharply:

"You are talking rubbish!"

"Oh, no, I am not. It was early in the morning. You bluffed your way into Mrs.

Lorrimer's room, where she was still heavily asleep under the influence of the drug

she had taken the night before. You bluff again--pretend to see at a glance that she is dead! You pack the parlourmaid off for brandy--hot water--all the rest of it. You

are left alone in the room. The maid has only had the barest peep. And then what

happens?

"You may not be aware of the fact, Dr. Roberts, but certain firms of window

cleaners specialise in early morning work. A window cleaner with his ladder

arrived at the same time as you did. He placed his ladder against the side of the

house and began his work. The first window he tackled was that of Mrs. Lorrirner's

room. When, however, he saw what was going on, he quickly retired to another

window, but he had seen sornethingfirst. He shall tell us his own story."

Poirot stepped lightly across the floor, turned a door handle, called:

"Come in, Stephens," and returned.

A big awkward-looking man with red hair entered. In his hand he held a

uniformed hat bearing the legend "Chelsea Window Cleaners' a.s.sociation" Which he twirled awkwardly.

Poirot said:

"Is there anybody you reeognise in this room?"

The man looked round, then gave a bashful nod of the head towards Dr.

Roberts.

"Him," he said.

"Tell us when you saw him last and what he was doing."

"This morning it was. Eight o'clock job at a lady's house in Cheyne Lane. I

started on the windows there. Lady was in bed. Looked ill she did. She was just

turning her head round on the pillow. This gent I took to be a doctor. He shoved her sleeve up and jabbed something into her arm just about here "he gestured. "She just dropped back on the pillow again. I thought I'd better hop it to another window, so I did. Hope I didn't do wrong in any way?"

"You did admirably, my friend," said Poirot.

He said quietly: "Eh bien, Dr. Roberts?"

"A--a simple restorative---" stammered Roberts. "A last hope of bringing her round. It's monstrous "

Poirot interrupted him.

"A simple restorative?--N-methyl-cyclo-hexenyl-methyl-malonyl urea," said Poirot. He rolled out the syllables unctuously. "Known more simply as Evipan.

Used an as anaesthetic for short operations. Injected intravenously in large doses it produces instant unconsciousness. It is dangerous to use it after veronal or any barbiturates have been given. I noticed the bruised place on her arm where something had obviously been injected into a vein. A hint to the police surgeon and the drug was easily discovered by no less a person than Sir Charles Imphrey, the Home Office a.n.a.lyst."

"That about cooks your goose, I think," said Superintendent Battle. "No need to prove the Shaitana business, though, of course, if necessary we can bring a further charge as to the murder of Mr. Charles Craddockand possibly his Wife dso."

The mention of those two names finished Roberts. He leaned back in his chair.

"I throw in my hand," he said. "You've got me! I suppose that sly devil Shaitana put you wise before you came that evening. And I thought I'd settled his hash so nicely."

"It isn't Shaitana you've got to thank," said Battle. "The honours lie with M. Poirot here."

He went to the door and two men entered.

Superintendent Battle's voice became official as he made the formal arrest.

As the door closed behind the accused man Mrs. Oliver said happily, if not quite truthfully: "I always said he did it!"

CHAPTER 31

It was Poirot's moment, every face was turned to his in eager antic.i.p.ation.

"You are very kind," he said, smiling. "You know, I think, that I enjoy my little lecture. I am a prosy old fellow.

"This case, to my mind, has been one of the most interesting cases I have ever come across. There was nothing, you see, to go upon. There were four people, one of whom must have committed the crime but which of the four? Was there anything to tell one? In the material sense--no. There were no tangible clues---no fingerprints--no incriminating papers or doc.u.ments. There were only--the people themselves.

"And one tangible cluethe bridge scores.

"You may remember that from the beginning I showed a particular interest in those scores. They told me something about the various people who had kept them and they did more. They gave me one valuable hint. I noticed at once, in the third rubber, the figure of 1500 above the line. That figure could only represent one thing--a call of grand slam. Now if a person were to make up their minds to commit a crime under these somewhat unusual circ.u.mstances (that is, during a rubber game of bridge) that person was clearly running two serious risks. The first was that the victim might cry out and the second was that even ffthe victim did not cry out some one of the other three might chance to look up at the psychological moment and actually witness the deed.

"Now as to the first risk, nothing could be done about it. It was a matter of a gambler's luck. But something could be done about the second. It stands to reason.

that during an interesting or an exciting hand the attention of the three players would be wholly on the game, whereas during a dull hand they were more likely to be looking about them. Now a bid of grand slam is always exciting. It is very often (as in this case it was) doubled. Every one of the three players is playing with close attention--the declarer to get his contract, the adversaries to discard correctly and to get him down. It was, then, a distinct possibility that the murder was committed during this particular hand and I determined to find out, if I could, exactly how the bidding had gone. I soon discovered that dummy during this particular hand had been Dr. Roberts. I bore that in mind and approached the matter from my second anglepsychological probability. Of the four suspects Mrs.