“With a pair of poisoned nail-scissors,” interrupted Giles derisively. “Go on, I like to see you becoming romantic.”

Hannasyde smiled. “I know. But it's no joke, Mr Carrington. Suppose she inflicted the scratch, seemingly by accident, and then bathed it with lotion into which she'd dropped her poison?”

Just a moment,” said Giles. “Is Harriet Matthews the eccentric lady with the economy-mania?”

“That's the one.”

“Out of all your suspects what a choice to make! She wouldn't have the sense, let alone the knowledge.”

“Voluble and eccentric ladies aren't always so guileless as they seem, Mr Carrington. Not that I think it was she. I don't. But the trouble is there's no one I think it was. On the face of it the heir's the likeliest suspect. He lives high, probably beyond his income, and, if I'm not much mistaken, bets a lot. Clever fellow, and looks pretty coldblooded. What's more, he presented me with a detailed alibi which I don't expect to pick the smallest hole in. And I haven't, so far, a thing on him. He says he heard of his uncle's death through you. How did he take it?”

Giles reflected. “It was over the telephone, you know. Quite calmly, I think. I merely said that Matthews was dead, and added that there seemed to be some doubt about the cause of death, and that there was to be an autopsy.” He paused “He sounded distinctly annoyed about that, but I think one would be. No one likes a scandal in the home circle, after all.”

“What did he say?”

“I don't remember. Something about the incompetence of doctors, and that he'd better come round and see me.”

“Oh, he came to see you that day, did he? When?”