p awake, you know. Won't do to go to
sleep."

"Ver' well," he replied drowsily. "Sorry t' give you all this trouble.
L' keep awake. But I think you're mistak'n--"

"He says it's very important that you shouldn't go to sleep, and that I
am to see that you don't. Do you understand?"

"Yes, I un'stan'. But why does this gennlem'n--?"

"Now it's of no use for you to ask a lot of questions," Mrs. Schallibaum
said playfully; "we'll talk to you to-morrow. Good night, doctor. I'll
light you down the stairs, but I won't come down with you, or the
patient will be falling asleep again."

Taking this definite dismissal, I retired, followed by a dreamily
surprised glance from the sick man. The housekeeper held the candle over
the balusters until I reached the bottom of the stairs, when I perceived
through the open door along the passage a glimmer of light from the
carriage lamps. The coachman was standing just outside, faintly
illuminated by the very dim lamplight, and as I stepped into the
carriage he remarked in his Scotch dialect that I "seemed to have been
makin' a nicht of it." He did not wait for any reply--none being in fact
needed--but shut the door and locked it.

I lit my little pocket-lamp and hung it on the back cushion. I even drew
the board and notebook from my pocket. But it seemed rather unnecessary
to take a fresh set of notes, and, to tell the truth, I rather shirked
the labour, tired as I was after my late exertions; besides, I wanted
to think over the events of the evening, while they were fresh in my
memory. Accordingly I put away the notebook, filled and lighted my pipe,
and settled myself to review the incidents attending my second visit to
this rather uncanny house.

Considered in leisurely retrospect, that visit offered quite a number of
problems that called for elucidation. There was the patient's condition,
for instance. Any doubt as to the cause of his symptoms was set at rest
by the effect of the antidotes. Mr. Graves was certainly under the
influence of morphine, and the only doubtful question was how he had
become so. That he had taken the poison himself was incredible. No
morphinomaniac would take such a knock-down dose. It was practically
certain that the poison had been administered by someone else, and, on
Mr. Weiss's own showing, there was no one but himself and the
housekeeper who could have administered it. And to this conclusion all
the other very queer circumstances pointed.

What we