Anyhow my thoughts flew to the pistol.  I took it out, and ran on to the landing.  Then I heard a sort of scream, or rather a call for help, and ran into this room.  The room was dark, for the lamp beside the Nurse was out, and the only light was that from the landing, coming through the open door.  Miss Trelawny was kneeling on the floor beside her father, and was screaming.  I thought I saw something move between me and the window; so, without thinking, and being half dazed and only half awake, I shot at it.  It moved a little more to the right between the windows, and I shot again.  Then you came up out of the big chair with all that muffling on your face.  It seemed to me, being as I say half dazed and half awake—­I know, sir, you will take this into account—­as if it had been you, being in the same direction as the thing I had fired at.  And so I was about to fire again when you pulled off the wrap.”  Here I asked him—­I was cross-examining now and felt at home: 

“You say you thought I was the thing you fired at.  What thing?” The man scratched his head, but made no reply.

“Come, sir,” I said, “what thing; what was it like?” The answer came in a low voice: 

“I don’t know, sir.  I thought there was something; but what it was, or what it was like, I haven’t the faintest notion.  I suppose it was because I had been thinking of the pistol before I went to sleep, and because when I came in here I was half dazed and only half awake—­which I hope you will in future, sir, always remember.”  He clung to that formula of excuse as though it were his sheet-anchor.  I did not want to antagonise the man; on the contrary I wanted to have him with us.  Besides, I had on me at that time myself the shadow of my own default; so I said as kindly as I knew how: 

“Quite right!  Sergeant.  Your impulse was correct; though of course in the half-somnolent condition in which you were, and perhaps partly affected by the same influence—­whatever it may be—­which made me sleep and which has put the Nurse in that cataleptic trance, it could not be expected that you would paused to weigh matters.  But now, whilst the matter is fresh, let me see exactly where you stood and where I sat.  We shall be able to trace the course of your bullets.”  The prospect of action and the exercise of his habitual skill seemed to brace him at once; he seemed a different man as he set about his work.  I asked Mrs. Grant to hold the tourniquet, and went and stood where he had stood and looked where, in the darkness, he had pointed.  I could not but notice the mechanical exactness of his mind, as when he showed me where he had stood, or drew, as a matter of course, the revolver from his pistol pocket, and pointed with it.  The chair from which I had risen still stood in its place.  Then I asked him to point with his hand only, as I wished to move in the track of his shot.

Just behind my chair, and a little back of it, stood a high buhl cabinet.  The glass door was shattered.  I asked: