“Who told you of my identity?” asked Poirot.
“Who told me? Miss Peabody told me. She saw through you all right!”
“Miss Peabody—yes.” Poirot sounded reflective. “I rather thought—”
Dr. Grainger cut in angrily.
“Now then, sir, I’m waiting for your explanation!”
“Certainly. My explanation is very simple. Attempted murder.”
“What? What’s that?”
Poirot said quietly:
“Miss Arundell had a fall, did she not? A fall down the stairs shortly before her death?”
“Yes, what of it? She slipped on that damned dog’s ball.”
Poirot shook his head.
“No, Doctor, she did not. A thread was fastened across the top of the stairs so as to trip her up.”
Dr. Grainger stared.
“Then why didn’t she tell me so?” he demanded. “Never said a word to me about it.”
“That is perhaps understandable—if it were a member of her own family who placed that thread there!”
“H’m—I see.” Grainger cast a sharp glance at Poirot, then threw himself into a chair. “Well?” he said. “How did you come to be mixed up in this affair?”
“Miss Arundell wrote to me, stressing the utmost secrecy. Unfortunately the letter was delayed.”
Poirot proceeded to give certain carefully edited details and explained the finding of the nail driven into the skirting board.
The doctor listened with a grave face. His anger had abated. “You can comprehend my position was a difficult one,” Poirot finished. “I was employed, you see, by a dead woman. But I counted the obligation none the less strong for that.”
Dr. Grainger’s brows were draw
n together in thought.
“And you’ve no idea who it was stretched that thread across the head of the stairs?” he asked.
“I have no evidence as to who it was. I will not say I have no idea.”
“It’s a nasty story,” said Grainger, his face grim.
“Yes. You can understand, can you not, that to begin with I was uncertain whether there had or had not been a sequel?”
“Eh? What’s that?”
“To all intents and purposes Miss Arundell died a natural death, but could one be sure of that? There had been one attempt on her life. How could I be sure that there had not been a second? And this time a successful one!”
Grainger nodded thoughtfully.
“I suppose you are sure, Dr. Grainger—please do not get angry—that Miss Arundell’s death was a natural one? I have come across certain evidence today—”
He detailed the conversation he had had with old Angus, Charles Arundell’s interest in the weed killer, and finally the old man’s surprise at the emptiness of the tin.