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