Dumb Witness (Hercule Poirot 16)

“I will do what I can. Au revoir, mademoiselle, au revoir, doctor.”

“Oh, go away!” cried Theresa. “And take St. Leonards with you. I wish I’d never set eyes on either of you.”

We left the room. Poirot did not this time deliberately place his ear to the crack but he dallied—yes, he dallied.

And not in vain. Theresa’s voice rose clear and defiant:

“Don’t look at me like that, Rex.”

And then suddenly, with a break in her voice—“Darling.” Dr. Donaldson’s precise voice answered her.

He said very clearly: “That man means mischief.”

Poirot grinned suddenly. He drew me through the front door. “Come, St. Leonards,” he said. “C’est drôle, ça!” Personally I thought the joke a particularly stupid one.

Twenty-five

I LIE BACK AND REFLECT

No, I thought, as I hurried after Poirot, there was no doubt about it now. Miss Arundell had been murdered and Theresa knew it. But was she herself the criminal or was there another explanation?

She was afraid—yes. But was she afraid for herself or for someone else? Could that someone be the quiet, precise young doctor with the calm, aloof manner?

Had the old lady died of genuine disease artificially induced?

Up to a point it all fitted in—Donaldson’s ambitions, his belief that Theresa would inherit money at her aunt’s death. Even the fact that he had been at dinner there on the evening of the accident

. How easy to leave a convenient window open and return in the dead of night to tie the murderous thread across the staircase. But then, what about the placing of the nail in position?

No, Theresa must have done that. Theresa, his fiancée and accomplice. With the two of them working in together, the whole thing seemed clear enough. In that case it was probably Theresa who had actually placed the thread in position. The first crime, the crime that failed, had been her work. The second crime, the crime that had succeeded, was Donaldson’s more scientific masterpiece.

Yes—it all fitted in.

Yet even now there were loose strands. Why had Theresa blurted out those facts about inducing liver disease in human beings? It was almost as though she did not realize the truth… But in that case—and I felt my mind growing bewildered, and I interrupted my speculations to ask:

“Where are we going, Poirot?”

“Back to my flat. It is possible that we may find Mrs. Tanios there.”

My thoughts switched off on a different track.

Mrs. Tanios! That was another mystery! If Donaldson and Theresa were guilty, where did Mrs. Tanios and her smiling husband come in? What did the woman want to tell Poirot and what was Tanios’ anxiety to prevent her doing so?

“Poirot,” I said humbly. “I’m getting rather muddled. They’re not all in it, are they?”

“Murder by a syndicate? A family sydicate? No, not this time. There is the mark of one brain and one brain only in this. The psychology is very clear.”

“You mean that either Theresa or Donaldson did it—but not both of them? Did he get her to hammer that nail in on some entirely innocent pretext, then?”

“My dear friend, from the moment I heard Miss Lawson’s story I realized that there were three possibilities. (1) That Miss Lawson was telling the exact truth. (2) That Miss Lawson had invented the story for reasons of her own. (3) That Miss Lawson actually believed her own story, but that her identification rested upon the brooch—and as I have already pointed out to you—a brooch is easily detachable from its owner.”

“Yes, but Theresa insists that the brooch did not leave her possession.”

“And she is perfectly right. I had overlooked a small but intensely significant fact.”

“Very unlike you, Poirot,” I said solemnly.

“N’est ce pas? But one has one’s lapses.”