Our visitor’s face had turned ashen gray as he listened to the words of his accuser. Now he sat for some time in thought with his face sunk in his hands. Then with a sudden impulsive gesture he plucked a photograph from his breast-pocket and threw it on the rustic table before us.

“That is why I have done it,” said he.

It showed the bust and face of a very beautiful woman. Holmes stooped over it.

“Brenda Tregennis,” said he.

“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 Ubanghi 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.