There was a prolonged silence in the room, in which I heard the gurgling of the oil in the lamp and the click of the coals and the heavy breathing of our host.  The most unwelcome sensations were creeping about my spine, and I wondered whether my companion would scorn me utterly if I asked to sleep on the sofa in his room.  It was eleven o’clock, I saw by the clock on the mantelpiece.  We had crossed the dividing line and were now well in the movement of the adventure.  The fight between my interest and my dread became acute.  But, even if turning back had been possible, I think the interest would have easily gained the day.

“I have enemies, of course,” I heard the Colonel’s rough voice break into the pause presently, “and have discharged a number of servants—–­”

“It’s not that,” put in John Silence briefly.

“You think not?  In a sense I am glad, and yet—­there are some things that can be met and dealt with—­”

He left the sentence unfinished, and looked down at the floor with an expression of grim severity that betrayed a momentary glimpse of character.  This fighting man loathed and abhorred the thought of an enemy he could not see and come to grips with.  Presently he moved over and sat down in the chair between us.  Something like a sigh escaped him.  Dr. Silence said nothing.

“My sister, of course, is kept in ignorance, as far as possible, of all this,” he said disconnectedly, and as if talking to himself.  “But even if she knew she would find matter-of-fact explanations.  I only wish I could.  I’m sure they exist.”

There came then an interval in the conversation that was very significant.  It did not seem a real pause, or the silence real silence, for both men continued to think so rapidly and strongly that one almost imagined their thoughts clothed themselves in words in the air of the room.  I was more than a little keyed up with the strange excitement of all I had heard, but what stimulated my nerves more than anything else was the obvious fact that the doctor was clearly upon the trail of discovery.  In his mind at that moment, I believe, he had already solved the nature of this perplexing psychical problem.  His face was like a mask, and he employed the absolute minimum of gesture and words.  All his energies were directed inwards, and by those incalculable methods and processes he had mastered with such infinite patience and study, I felt sure he was already in touch with the forces behind these singular phenomena and laying his deep plans for bringing them into the open, and then effectively dealing with them.