For a long time I wandered aimlessly up and down, and about midnight I started for home.  I was very calm and very tired.  My janitor opened the door at once, which was quite unusual for him, and I thought that another lodger had probably just come in.

When I go out I always double-lock the door of my room, and I found it merely closed, which surprised me; but I supposed that some letters had been brought up for me in the course of the evening.

I went in, and found my fire still burning so that it lighted up the room a little, and, while in the act of taking up a candle, I noticed somebody sitting in my armchair by the fire, warming his feet, with his back toward me.

I was not in the slightest degree frightened.  I thought, very naturally, that some friend or other had come to see me.  No doubt the porter, to whom I had said I was going out, had lent him his own key.  In a moment I remembered all the circumstances of my return, how the street door had been opened immediately, and that my own door was only latched and not locked.

I could see nothing of my friend but his head, and he had evidently gone to sleep while waiting for me, so I went up to him to rouse him.  I saw him quite distinctly; his right arm was hanging down and his legs were crossed; the position of his head, which was somewhat inclined to the left of the armchair, seemed to indicate that he was asleep.  “Who can it be?” I asked myself.  I could not see clearly, as the room was rather dark, so I put out my hand to touch him on the shoulder, and it came in contact with the back of the chair.  There was nobody there; the seat was empty.

I fairly jumped with fright.  For a moment I drew back as if confronted by some terrible danger; then I turned round again, impelled by an imperious standing upright, panting with fear, so upset that I could not collect my thoughts, and ready to faint.

But I am a cool man, and soon recovered myself.  I thought:  “It is a mere hallucination, that is all,” and I immediately began to reflect on this phenomenon.  Thoughts fly quickly at such moments.

I had been suffering from an hallucination, that was an incontestable fact.  My mind had been perfectly lucid and had acted regularly and logically, so there was nothing the matter with the brain.  It was only my eyes that had been deceived; they had had a vision, one of those visions which lead simple folk to believe in miracles.  It was a nervous seizure of the optical apparatus, nothing more; the eyes were rather congested, perhaps.

I lit my candle, and when I stooped down to the fire in doing so I noticed that I was trembling, and I raised myself up with a jump, as if somebody had touched me from behind.

I was certainly not by any means calm.

I walked up and down a little, and hummed a tune or two.  Then I double-locked the door and felt rather reassured; now, at any rate, nobody could come in.