“The next morning at breakfast, I mentioned casually to my mother that she had ‘dropped off,’ and I had shut the door for her.  To my surprise, she assured me she had never been out of her room.  I reminded her about the two raps she had given upon the banister; but she still was certain I must be mistaken; and in the end I teased her, saying she had grown so accustomed to my bad habit of sitting up late, that she had come to call me in her sleep.  Of course, she denied this, and I let the matter drop; but I was more than a little puzzled, and did not know whether to believe my own explanation, or to take the mater’s, which was to put the noises down to the mice, and the open door to the fact that she couldn’t have properly latched it, when she went to bed.  I suppose, away in the subconscious part of me, I had a stirring of less reasonable thoughts; but certainly, I had no real uneasiness at that time.

“The next night there came a further development.  About two thirty a.m., I heard my mother’s door open, just as on the previous night, and immediately afterward she rapped sharply, on the banister, as it seemed to me.  I stopped my work and called up that I would not be long.  As she made no reply, and I did not hear her go back to bed, I had a quick sense of wonder whether she might not be doing it in her sleep, after all, just as I had said.

“With the thought, I stood up, and taking the lamp from the table, began to go toward the door, which was open into the passage.  It was then I got a sudden nasty sort of thrill; for it came to me, all at once, that my mother never knocked, when I sat up too late; she always called.  You will understand I was not really frightened in any way; only vaguely uneasy, and pretty sure she must really be doing the thing in her sleep.

“I went quickly up the stairs, and when I came to the top, my mother was not there; but her door was open.  I had a bewildered sense though believing she must have gone quietly back to bed, without my hearing her.  I entered her room and found her sleeping quietly and naturally; for the vague sense of trouble in me was sufficiently strong to make me go over to look at her.

“When I was sure that she was perfectly right in every way, I was still a little bothered; but much more inclined to think my suspicion correct and that she had gone quietly back to bed in her sleep, without knowing what she had been doing.  This was the most reasonable thing to think, as you must see.

“And then it came to me, suddenly, that vague, queer, mildewy smell in the room; and it was in that instant I became aware I had smelt the same strange, uncertain smell the night before in the passage.

“I was definitely uneasy now, and began to search my mother’s room; though with no aim or clear thought of anything, except to assure myself that there was nothing in the room.  All the time, you know, I never expected really to find anything; only my uneasiness had to be assured.