"Yes, Brenda Tregennis," repeated our visitor. "For years I have loved her. For years she has loved me. There is the secret of that Cornish seclusion which people have marvelled at. It has brought me close to the one thing on earth that was dear to me. I could not marry her, for I have a wife who has left me for years and yet whom, by the deplorable laws of England, I could not divorce. For years Brenda waited. For years I waited. And this is what we have waited for." A terrible sob shook his great frame, and he clutched his throat under his brindled beard. Then with an effort he mastered himself and spoke on:

"The vicar knew. He was in our confidence. He would tell you that she was an angel upon earth. That was why he telegraphed to me and I returned. What was my baggage or Africa to me when I learned that such a fate had come upon my darling? There you have the missing clue to my action, Mr. Holmes."

"Proceed," said my friend.

Dr. Sterndale drew from his pocket a paper packet and laid it upon the table. On the outside was written "Radix pedis diaboli" with a red poison label beneath it. He pushed it towards me. "I understand that you are a doctor, sir. Have you ever heard of this preparation?"

"Devil's-foot root! No, I have never heard of it."

"It is no reflection upon your professional knowledge," said he, "for I believe that, save for one sample in a laboratory at Buda, there is no other specimen in Europe. It has not yet found its way either into the pharmacopoeia or into the literature of toxicology. The root is shaped like a foot, half human, half goatlike; hence the fanciful name given by a botanical missionary. It is used as an ordeal poison by the medicine-men in certain districts of West Africa and is kept as a secret among them. This particular specimen I obtained under very extraordinary circumstances in the Ubangi country." He opened the paper as he spoke and disclosed a heap of reddish-brown, snuff-like powder.

"Well, sir?" asked Holmes sternly.

"I am about to tell you, Mr. Holmes, all that actually occurred, for you already know so much that it is clearly to my interest that you should know all. I have already explained the relationship in which I stood to the Tregennis family. For the sake of the sister I was friendly with the brothers. There was a family quarrel about money which estranged this man Mortimer, but it was supposed to be made up, and I afterwards met him as I did the others. He was a sly, subtle, scheming man, and several things arose which gave me a suspicion of him, but I had no cause for any positive quarrel.

"One day, only a couple of weeks ago, he came down to my cottage and I showed him some of my African curiosities. Among other things I exhibited this powder, and I told him of its strange properties, how it stimulates those brain centres which control the emotion of fear, and how either madness or death is the fate of the unhappy native who is subjected to the ordeal by the priest of his tribe. I told him also how powerless European science would be to detect it. How he took it I cannot say, for I never left the room, but there is no doubt that it was then, while I was opening cabinets and stooping to boxes, that he managed to abstract some of the devil's-foot root. I well remember how he plied me with questions as to the amount and the time that was needed for its effect, but I little dreamed that he could have a personal reason for asking.

"I thought no more of the matter until the vicar's telegram reached me at Plymouth. This villain had thought that I would be at sea before the news could reach me, and that I should be lost for years in Africa. But I returned at once. Of course, I could not listen to the details without feeling assured that my poison had been used. I came round to see you on the chance that some other explanation had suggested itself to you. But there could be none. I was convinced that Mortimer Tregennis was the murderer; that for the sake of money, and with the idea, perhaps, that if the other members of his family were all insane he would be the sole guardian of their joint property, he had used the devil's-foot powder upon them, driven two of them out of their senses, and killed his sister Brenda, the one human being whom I have ever loved or who has ever loved me. There was his crime; what was to be his punishment?