“I beg your pardon, sir,” I stammered. “I was trying to explain to Inspector Charles that it wouldn’t do to annoy Weathered’s patients with inquiries into their private lives unless there were some grounds for suspicion against them.” Tarleton stepped to the telephone. “You have heard what Dr. Cassilis said? He is perfectly right. We have no concern with any patient of Weathered’s who is not implicated in the murder. The moment we can dismiss them from the case they must be let alone.” I hardly know whether I was more astonished or delighted at this handsome endorsement of my words. But I was not yet out of the wood. My chief made the Inspector repeat the information he had just given to me, and Charles naturally took the opportunity to defend himself. Apparently the Inspector explained to Tarleton that I had not seemed satisfied at first with his report about Lady Violet having gone to Herefordshire before the night of the dance. It was the physician’s turn to show surprise. “Why did you question Lady Violet Bredwardine’s alibi, Cassilis?” It gratified me to feel that the Inspector had done me a good turn unawares. “I merely thought it right to ask Captain Charles if he was quite satisfied before I took the responsibility of reporting the alibi to you. He offered to send a man down to make inquiries at Lord Ledbury’s seat, and I asked him to take no further steps without your sanction.” My chief smiled with the utmost amiability. “Dr. Cassilis has exactly understood my views,” he said through the telephone. “There is not the least necessity for you to trouble yourself further about Lady Violet for the present. The person in whom I am interested just now is Captain Armstrong, R.A. He is a Fellow of the Royal Geographical Society, and a well-known traveller and explorer. I shall be glad if you can let me have his present address.” There was a brief pause. It was evident that the Inspector had been consulting his note-book, for his reply, which I failed to catch, provoked Tarleton to say testily, “I know, I know. He is not on the books of the Club. I want to get in touch with him for another reason. I think he may be of help in enabling me to decide on the cause of death.” As soon as Captain Charles had been disposed of, the physician came to the luncheon table and made a hasty meal. I reported my failure to obtain any definite proof of the existence of leopards in Sumatra, and found that the point had lost its importance in his eyes. “I have been to the British Museum Reading Room,” he told me. “I met Captain Armstrong about two years ago, after reading his book on Sumatra, but I had forgotten his name, and I had to look through the subject index under the head of Sumatra to find it. Then I got out his book, _Across Sumatra_, and saw from the title-page that he had also written a book on West Africa, where everyone knows there are leopards, so that he had plenty of opportunities of procuring skins and claws.”