Watson straightened up with an effort.

“This is the house,” he spoke.  “I came here a year ago.  I go away tonight.  I had hoped to find it.  I promised Bertha.  I came alone.  I had reasons to believe I had solved it.  I found the Rhamda and the Nervina.  I had iron will and courage—­also strength.  The Rhamda was never able to control me.  My life is gone but not my will.  Now I have left him another.  Do not surrender, Harry.  It is a gruesome task; but hold on to the end.  Help me up the steps.  There now.  Just wait a minute till I fetch a stimulant.”

He did not ring for a servant.  That I noticed.  Instead he groped about for a key, unlocked the door and stumbled into a room.  He fumbled for a minute among some glasses.

“Will you switch on a light?” he asked.

Hobart struck a match; when he found it he pressed the switch.

The room in which we were standing was a large one, fairly well furnished, and lined on two sides with bookshelves; in the centre was an oak table cluttered with papers, a couple of chairs, and on one of them, a heavy pipe, which, somehow, I did not think of as Watson’s.  He noticed my look.

“Jerome’s,” he explained.  “We live here—­Jerome, the detective, and myself.  He has been here since the day of the doctor’s disappearance.  I came here a year ago.  He is in Nevada at present.  That leaves me alone.  You will notice the books, mostly occult:  partly mine, partly the detective’s.  We have gone at it systematically from the beginning.  We have learned almost everything but what would help us.  Mostly sophistry—­and guesswork.  Beats all how much ink has been wasted to say nothing.  We were after the Blind Spot.”

“But what is it?  Is it in this house?”

“I can answer one part of your question,” he answered, “but not the other.  It is here somewhere, in some place.  Jerome is positive of that.  You remember the old lady?  The one who died?  Her actions were rather positive even if feeble.  She led Jerome to this next room.”  He turned and pointed; the door was open.  I could see a sofa and a few chairs; that was all.

“It was in here.  The bell.  Jerome never gets tired of telling.  A church bell.  In the centre of the room.  At first I didn’t believe; but now I accept it all.  I know, but what I know is by intuition.”

“Sort of sixth sense?’

“Yes.  Or foresight.”

“You never saw this bell nor found it?  Never were able to arrive at an explanation?”

“No.”

“How about the Rhamda?  The Nervina?  Do they come to this house?”

“Not often.”

“How do they come in?  Through the window?”

He smiled rather sadly.  “I don’t know.  At least they come.  You shall see them yourself.  The Rhamda still has something to do with Dr. Holcomb.  Somehow his very concern tells me the doctor is safe.  Undoubtedly the professor made a great discovery.  But he was not alone.  He had a co-worker—­the Rhamda.  For reasons of his own the Rhamda wishes to control the Blind Spot.”