“Thank you so much,” he said. “You’ve been extremely courteous. You’ve no idea how scared we are of experts at the Yard.”

“Indeed?”

“Yes, indeed. This must have been a distressing business for you.”

“Very.”

“I believe Sir Derek was a personal friend.”

“I knew him personally—yes.”

“Had you seen much of him recently?”

Phillips did not answer immediately. Then, looking straight in front of him, he said: “What do you call recently?”

“Well—a fortnight or so.”

“I called at his house on the Friday evening before the operation.”

“A professional call?”

“No.”

“Did you think he was heading for a serious illness then?”

“I did not know there was anything the matter with him.”

“He did not mention a patent medicine?”

“No,” said Phillips sharply. “What is this about patent medicines?”

“Merely a point that arises.”

“If there is any question of his taking a drug,” said Phillips more cordially, “it should be gone into most thoroughly.”

“That is my view,” Alleyn answered coolly.

“He may,” Phillips went on, “have had an idiosyncrasy for hyoscine and if he had been taking it—”

“Exactly.”

The two men seemed to have changed positions. It was the surgeon who now made the advances. Alleyn was polite and withdrawn.

“Is there any evidence that O’Callaghan had taken a patent medicine?”

“It’s possible.”

“Damn’ fool!” ejaculated Phillips.

“Strange he didn’t tell you he was ill on the Friday.”

“He—I—we discussed another matter altogether.”

“Would you care to tell me what it was?”

“It was purely personal.”

“Sir John,” said Alleyn mildly, “I think I should let you know at once that I have seen your letter to Sir Derek.”

Phillips’s head jerked up as though he had come suddenly face to face with a threatening obstacle. He did not speak for perhaps half a minute and then he said very softly:

“Do you enjoy reading other people’s private correspondence?”

“About as much as you enjoy glaring into a septic abdomen, I should think,” rejoined Alleyn. “It has a technical interest.”

“I suppose you’ve spoken to the butler?”

“Would you like to give me your own explanation of the business?”

“No,” said Phillips. “No.”

“Speaking unofficially—a thing I am far too prone to do—I am extremely sorry for you, Sir John.”

Phillips looked at him.

“Do you know, I think I believe you,” he said. “Is there anything else?”

“No, I’ve kept you quite long enough. Would it be an awful bore for everyone if I had a word with the nurses who attended the case?”

“I don’t think they can tell you very much further.”

“Probably not, but I think I ought to see them unless they are all heavily engaged in operations.”

“The theatre is not in use at the moment. The matron and the nurse who assists her—Nurse Banks—will be free.”