case--that of Mortimer Tregennis himself--you cannot have forgotten
the horrible stuffiness of the room when we arrived, though the
servant had thrown open the window. That servant, I found upon
inquiry, was so ill that she had gone to her bed. You will admit,
Watson, that these facts are very suggestive. In each case there is
evidence of a poisonous atmosphere. In each case, also, there is
combustion going on in the room--in the one case a fire, in the other
a lamp. The fire was needed, but the lamp was lit--as a comparison of
the oil consumed will show--long after it was broad daylight. Why?
Surely because there is some connection between three things--the
burning, the stuffy atmosphere, and, finally, the madness or death of
those unfortunate people. That is clear, is it not?"
"It would appear so."
"At least we may accept it as a working hypothesis. We will suppose,
then, that something was burned in each case which produced an
atmosphere causing strange toxic effects. Very good. In the first
instance--that of the Tregennis family--this substance was placed in
the fire. Now the window was shut, but the fire would naturally carry
fumes to some extent up the chimney. Hence one would expect the
effects of the poison to be less than in the second case, where there
was less escape for the vapour. The result seems to indicate that it
was so, since in the first case only the woman, who had presumably
the more sensitive organism, was killed, the others exhibiting that
temporary or permanent lunacy which is evidently the first effect of
the drug. In the second case the result was complete. The facts,
therefore, seem to bear out the theory of a poison which worked by
combustion.
"With this train of reasoning in my head I naturally looked about in
Mortimer Tregennis's room to find some remains of this substance. The
obvious place to look was the talc shelf or smoke-guard of the lamp.
There, sure enough, I perceived a number of flaky ashes, and round
the edges a fringe of brownish powder, which had not yet been
consumed. Half of this I took, as you saw, and I placed it in an
envelope."
"Why half, Holmes?"
"It is not for me, my dear Watson, to stand in the way of the
official police force. I leave them all the evidence which I found.
The poison still remained upon the talc had they the wit to find it.
Now, Watson, we will light our lamp; we will, however, take the
precaution to open our window to avoid the premature decease of two
deserving members of society, and you will seat yourself near that
open window in an armchair unless, like a sensible man, you determine
to have nothing to do with the affair. Oh, you will see it out, will
you? I thought I knew my Watson. This chair I will place opposite
yours, so that we may be the same distance from the poison and face
to face. The door we will leave ajar. Each is now in a position to
watch the other and to bring the experiment to an end should the
symptoms seem alarming. Is that all clear? Well, then, I take our
powder--or what remains of it--from the envelope, and I lay it above
the burning lamp. So! Now, Watson, let us sit down and await
developments."
They were not long in coming. I had hardly settled in my chair before
I was conscious of a thick, musky odour, subtle and nauseous. At the
very first whiff of it my brain and my imagination were beyond all
control. A thick, black cloud swirled before my eyes, and my mind
told me that in this cloud, unseen as yet, but about to spring out
upon my appalled senses, lurked all that was vaguely horrible, all
that was monstrous and inconceivably wicked in the universe. Vague
shapes swirled and swam amid the dark cloud-bank, each a menace and a
warning of something coming, the advent of some unspeakable dweller
upon the threshold, whose very shadow would blast my soul. A freezing
horror took possession of me. I felt that my hair was rising, that my
eyes were protruding, that my mouth was opened, and my tongue like
leather. The turmoil within my brain was such that something must
surely snap. I tried to scream and was vaguely aware of some hoarse
croak which was my own voice, but distant and detached from myself.
At the same moment, in some effort of escape, I broke through that
cloud of despair and had a glimpse of Holmes's face, white, rigid,
and drawn with horror--the very look which I had seen upon the
features of the dead. It was that vision which gave me an instant of
sanity and of strength. I dashed from my chair, threw my arms round
Holmes, and together we lurched through the door, and an instant
afterwards had thrown ourselves down upon the grass plot and were
lying side by side, conscious only of the glorious sunshine which was
bursting its way through the hellish cloud of terror which had girt
us in. Slowly it rose from our souls like the mists from a landscape
until peace and reason had returned, and we were sitting upon the
grass, wiping our clammy foreheads, and looking with apprehension at
each other to mark the last traces of that terrific experience which
we had undergone.
"Upon my word, Watson!" said Holmes at last with an unsteady voice,
"I owe you both my thanks and an apology. It was an unjustifiable
experiment even for one's self, and doubly so for a friend. I am
really very sorry."
"You know," I answered with some emotion, for I have never seen so
much of Holmes's heart before, "that it is my greatest joy and
privilege to help you."
He relapsed at once into the half-humorous, half-cynical vein which
was his habitual attitude to those about him. "It would be
superfluous to drive us mad, my dear Watson," said he. "A candid
observer would certainly declare that we were so already before we
embarked upon so wild an experiment. I confess that I never imagined
that the effect could be so sudden and so severe." He dashed into the
cottage, and, reappearing with the burning lamp held at full arm's
length, he threw it among a bank of brambles. "We must give the room
a little time to clear. I take it, Watson, that you have no longer a
shadow of a doubt as to how these tragedies were produced?"
"None whatever."
"But the cause remains as obscure as before. Come into the arbour
here and let us discuss it together. That villainous stuff seems
still to linger round my throat. I think we must admit that all the
evidence points to this man, Mortimer Tregennis, having been the
criminal in the first tragedy, though he was the victim in the second
one. We must remember, in the first place, that there is some story
of a family quarrel, followed by a reconciliation. How bitter that
quarrel may have been, or how hollow the reconciliation we cannot
tell. When I think of Mortimer Tregennis, with the foxy face and the
small shrewd, beady eyes behind the spectacles, he is not a man whom
I should judge to be of a particularly forgiving disposition. Well,
in the next place, you will remember that this idea of someone moving
in the garden, which took our attention for a moment from the real
cause of the tragedy, emanated from him. He had a motive in
misleading 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, while he sprang forward with
clenched hands towards my companion. Then he stopped, and with a
violent effort he resumed a cold, rigid calmness, which was, perhaps,
more suggestive of danger than his hot-headed outburst.
"I have lived so long among savages and beyond the law," said he,
"that I have got into the way of being a law to myself. You would do
well, Mr. Holmes, not to forget it, for I have no desire to do you an
injury."
"Nor have I any desire to do you an injury, Dr. Sterndale. Surely the
clearest proof of it is that, knowing what I know, I have sent for
you and not for the police."
Sterndale sat down with a gasp, overawed for, perhaps, the first time
in his adventurous life. There was a calm assurance of power in
Holmes's manner which could not be withstood. Our visitor stammered
for a moment, his great hands opening and shutting in his agitation.
"What do you mean?" he asked at last. "If this is bluff upon your
part, Mr. Holmes, you have chosen a bad man for your experiment. Let
us have no more beating about the bush. What do you mean?"
"I will tell you," said Holmes, "and the reason why I tell you is
that I hope frankness may beget frankness. What my next step may be
will depend entirely upon the nature of your own defence."
"My defence?"
"Yes, sir."
"My defence against what?"
"Against the charge of killing Mortimer Tregennis."
Sterndale mopped his forehead with his handkerchief. "Upon my word,
you are getting on," said he. "Do all your successes depend upon this
prodigious power of bluff?"
"The bluff," said Holmes sternly, "is upon your side, Dr. Leon
Sterndale, and not upon mine. As a proof I will tell you some of the
facts upon which my conclusions are based. Of your return from
Plymouth, allowing much of your property to go on to Africa, I will
say nothing save that it first informed me that you were one of the
factors which had to be taken into account in reconstructing this
drama--"
"I came back--"
"I have heard your reasons and regard them as unconvincing and
inadequate. We will pass that. You came down here to ask me whom I
suspected. I refused to answer you. You then went to the vicarage,
waited outside it for some time, and finally returned to your
cottage."
"How do you know that?"
"I followed you."
"I saw no one."
"That is what you may expect to see when I follow you. You spent a
restless night at your cottage, and you formed certain plans, which
in the early morning you proceeded to put into execution. Leaving
your door just as day was breaking, you filled your pocket with some
reddish gravel that was lying heaped beside your gate."
Sterndale gave a violent start and looked at Holmes in amazement.
"You then walked swiftly for the mile which separated you from the
vicarage. You were wearing, I may remark, the same pair of ribbed
tennis shoes which are at the present moment upon your feet. At the
vicarage you passed through the orchard and the side hedge, coming
out under the window of the lodger Tregennis. It was now daylight,
but the household was not yet stirring. You drew some of the gravel
from your pocket, and you threw it up at the window above you."
