"Eh bien," said Poirot. "The case is ended.
The murderer of Mr. Shaitana is found at last."
"So Mrs. Oliver told me.
That pretty little thing, Anne Meredith.
I can hardly believe it.
A most unbelievable murderess."
"She was a murderess all right," said Battle.
"Three murders to her credit - and not her fault that she didn't get away with a fourth one."
"Incredible!" murmured Roberts.
"Not at all," said Mrs. Oliver. "Least likely person. It seems to work out in real life just the same as in books."
"It's been an amazing day," said Roberts. "First Mrs. Lorrimer's letter - I suppose that was a forgery, eh?"
"Precisely.
A forgery written in triplicate."
"She wrote one to herself, too?"
"Naturally.
The forgery was quite skillful - 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, Monsieur 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 a conclusion in my own mind as to the identity 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, soft and catlike.
"You see, Doctor 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, Monsieur 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 you standing for this?"
"I think you'd better listen to what Monsieur 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 eyewitness 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 parlormaid 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 Doctor Roberts, but certain firms of window cleaners specialize in early morning work.
A window cleaner with his ladder arrived at the same time as you did.