“Coming upstairs I found the old lady a bit perturbed.  I had told her my name; she had recognised me as well.

“‘Come with me,’ she said.

“With that she opened a door.  She was very old and very uncertain; yet she was scarcely afraid.

“’In there,” she said, and pointed through the door.

“I entered an ordinary room, furnished as a parlour.  There was a sofa, a table, a few chairs; little else.

“‘What do you mean?’ I asked.

“‘The man!’

“’The man!  What man?”

“‘Oh!’ she exclaimed, ’he came here one night when the moon was shining.  He sat down on the doorstep.  He was just the kind of a lad that’s in need of a mother.  So I asked him to lie on the sofa.  He was tired, you see, and—­I once had a son of my own.’

“She stopped, and it was a moment before she continued.  I could feel the pressure of her hand on my arm, pitiful, beseeching.

“’So I took him in there.  In there; see?  On that sofa.  I saw it!  They took him!  Oh, sir; it was terrible!’

“She was weird, uncanny, strangely interesting.

“’He just lay down there.  I was standing by the door when—­they took him!  I couldn’t understand, sir.  I saw the blue light; and the moon—­it was gone.  And then—­’ She looked up at me again and whispered:  ’And then I heard a bell—­a very beautiful bell—­a church bell, sir?  But you know, don’t you?  You are the great Dr. Holcomb.  That’s why you went into the cellar, wasn’t it?  Because you know!’

“Her manner as much as her story, impressed me.  I said: 

“’I must give this room a careful examination.  Would you be good enough to leave me to myself?’

“She closed the door after her.  I had the green stone in my hand; it was very heavy, and I placed it on one of the chairs.  The blue stone I still held.  At the moment I hadn’t the least notion of what was about to happen; it was all accident, from beginning to end.

“All of a sudden the room disappeared!  That is, the side wall; I was not looking at the dingy old wallpaper, but out through and into an immense building, dim, vast and immeasurable.

“Directly in front of me was a white substance like a stone of snow.  Upon this substance was seated a man, about my own age, as nearly as I could make out.  He looked up just as I noted him.

“Our recognition was mutual.  Immediately he made a sign with one hand.  And at once I took a step forward; I thought he had motioned.  It was all so real and natural.  Though his features were dim he could not have been more than ten feet distant.  But, at that very instant, when I made that one step, the whole thing vanished.

“I was still in the room at Chatterton Place!

“That’s what started it all.  Had this occurred to any one else in the world I should have labelled it an unaccountable illusion.  But it had happened to me.

“I had my theory; between the spiritual and the material there must be a point of contact.  And—­I had found it!  I had discovered the road to the Indies, to the Occult, to all that other men call unknowable.  And I called it—­