that weird journey and the strange, secret house to which it had brought
me, I could see that it offered a problem after his very heart. During
the whole of my narration he sat as motionless as a statue, evidently
committing the whole story to memory, detail by detail; and even when I
had finished he remained for an appreciable time without moving or
speaking.

At length he looked up at me. "This is a very extraordinary affair,
Jervis," he said.

"Very," I agreed; "and the question that is agitating me is, what is to
be done?"

"Yes," he said, meditatively, "that is the question; and an uncommonly
difficult question it is. It really involves the settlement of the
antecedent question: What is it that is happening at that house?"

"What do you think is happening at that house?" I asked.

"We must go slow, Jervis," he replied. "We must carefully separate the
legal tissues from the medical, and avoid confusing what we know with
what we suspect. Now, with reference to the medical aspects of the case.
The first question that confronts us is that of sleeping sickness, or
negro-lethargy as it is sometimes called; and here we are in a
difficulty. We have not enough knowledge. Neither of us, I take it, has
ever seen a case, and the extant descriptions are inadequate. From what
I know of the disease, its symptoms agree with those in your case in
respect of the alleged moroseness and in the gradually increasing
periods of lethargy alternating with periods of apparent recovery. On
the other hand, the disease is said to be confined to negroes; but that