leading us. Finally, if he
did not throw the substance into the fire at the moment of leaving the
room, who did do so? The affair happened immediately after his
departure. Had anyone else come in, the family would certainly have
risen from the table. Besides, in peaceful Cornwall, visitors did not
arrive after ten o'clock at night. We may take it, then, that all the
evidence points to Mortimer Tregennis as the culprit."

"Then his own death was suicide!"

"Well, Watson, it is on the face of it a not impossible supposition.
The man who had the guilt upon his soul of having brought such a fate
upon his own family might well be driven by remorse to inflict it upon
himself. There are, however, some cogent reasons against it.
Fortunately, there is one man in England who knows all about it, and I
have made arrangements by which we shall hear the facts this afternoon
from his own lips. Ah! he is a little before his time. Perhaps you
would kindly step this way, Dr. Leon Sterndale. We have been conducing
a chemical experiment indoors which has left our little room hardly fit
for the reception of so distinguished a visitor."

I had heard the click of the garden gate, and now the majestic figure
of the great African explorer appeared upon the path. He turned in
some surprise towards the rustic arbour in which we sat.

"You sent for me, Mr. Holmes. I had your note about an hour ago, and I
have come, though I really do not know why I should obey your summons."

"Perhaps we can clear the point up before we separate," said Holmes.
"Meanwhile, I am much obliged to you for your courteous acquiescence.
You will excuse this informal reception in the open air, but my friend
Watson and I have nearly furnished an additional chapter to what the
papers call the Cornish Horror, and we prefer a clear atmosphere for
the present. Perhaps, since the matters which we have to discuss will
affect you personally in a very intimate fashion, it is as well that we
should talk where there can be no eavesdropping."

The explorer took his cigar from his lips and gazed sternly at my
companion.

"I am at a loss to know, sir," he said, "what you can have to speak
about which affects me personally in a very intimate fashion."

"The killing of Mortimer Tregennis," said Holmes.

For a moment I wished that I were armed. Sterndale's fierce face
turned to a dusky red, his eyes glared, and the knotted, passionate
veins started out in his forehead,