“Then the professor is in this Blind Spot?”

“We think so.  At least it is our conjecture.  We do not know.”

“Then you don’t think it trickery?”

“No, hardly.  Harry, you know better than that.  Can you imagine the great doctor the dupe of a mere trickster?  The professor was a man of great science and was blessed with an almighty sound head.  But he had one weakness.”

Hobart spoke up.

“What is it, Chick?  I think I know what you mean.  The old boy was honest?”

“Exactly.  He had been a scholar all his life.  He taught ethics.  He believed in right.  He practised his creed.  When he came to the crucial experiment he found himself dealing with a rogue.  The Rhamda helped him just so far; but once he had the professor in his power it was not his purpose to release him until he was secure of the Blind Spot.”

“I see,” I spoke.  “The man is a villain.  I think we can handle him.”

But Watson shook his head.

“That’s just it, Harry!  The man!  If he were a man I could have handled him in short order.  That’s what I thought at first.  Don’t make any mistake.  Don’t try violence.  That’s the whole crux of the difficulty.  If he were only a man!  Unfortunately, he is not.”

“Not a man!” I exclaimed.  “What do you mean?  Then, what is he?”

“He is a phantom.”

I glanced at Hobart and caught his eye.  Hobart believed him!  The poor pallid face of Watson, the athlete; there was nothing left to him but his soul!  I shall not forget Watson as he sat there, his lean, long fingers grasping the brandy glass, his eyes burning and his life holding back from the pit through sheer will and courage.  Would I come to this?  Would I have the strength to measure up to his standard?

Hobart broke the tension.

“Chick’s right.  There is something in it, Harry.  Not all the secrets of the universe have been unlocked by any means.  Now, Chick, about details.  Have you any data—­any notes?”

Watson rose.  I could see he was grateful.

“You believe me, don’t you, Hobart?  It is good.  I had hoped to find someone, and I found you two.  Harry, remember what I have told you.  Hold the ring.  You take my place.  Whatever happens, stick out to the end.  You have Hobart here to help you.  Now just a minute.  The library is here; you can look over my books.  I shall return in a moment.”

He stepped out into the hall; we could hear his weary feet dragging down the hallway—­a hollow sound and a bit uncanny.  Somehow my mind rambled back to that account I had read in the newspaper—­Jerome’s story—­“Like weary bones dragging slippers.”  And the old lady.  Who was she?  Why was everyone in this house pulled down to exhaustion—­the words of the old lady, I could almost hear them; the dank air murmuring their recollection.  “Now there are two.  Now there are two!”

“What’s the matter, Harry?”