old enough for its beams to have rolled.  Yet the floor was certainly uneven, and, what was stranger yet, had, in sagging, failed to carry the base-board with it.  This I could see by peering around the side of the cabinet.  Was it an important enough fact to call for explanation?  Possibly not; yet when I had taken a short leap up and come down on what was certainly an unstable floor, I decided that I should never be satisfied till I had seen that cabinet removed and the floor under it rigidly examined.

Yet when I came to take a look at this projection from the library window and saw that this floor, like that of the many entrances, was only the height of one step from the ground, I felt the folly into which my inquiring spirit had led me, and would have dismissed the whole subject from my mind if my eyes had not detected at that moment on one of the tables an unusually thin paper-knife.  This gave me an idea.  Carrying it back with me into the recess, I got down on my knees, and first taking the precaution to toss a little stick-pin of mine under the cabinet to be reached after in case I was detected there by Nixon, I insinuated the cutter between the base-board and the floor and found that I could not only push it in an inch or more before striking the brick, but run it quite freely around from one corner of the recess to the other.  This was surely surprising.  The exterior of this vestibule must be considerably larger than the interior would denote.  What occupied the space between?  I went upstairs full of thought.  Sometime, and that before long, I would have that cabinet removed.

CHAPTER XIII

A DISCOVERY

Mrs. Packard came in very soon after this.  She was accompanied by two friends and I could hear them talking and laughing in her room upstairs all the afternoon.  It gave me leisure, but leisure was not what I stood in need of, just now.  I desired much more an opportunity to pursue my inquiries, for I knew why she had brought these friends home with her and lent herself to a merriment that was not natural to her.  She wished to forestall thought; to keep down dread; to fill the house so full of cheer that no whisper should reach her from that spirit-world she had come to fear.  She had seen—­or believed that she had seen—­a specter, and she had certainly heard a laugh that had come from no explicable human source.

The brightness of the sunshiny day aided her unconsciously in this endeavor.  But I foresaw the moment when this brightness would disappear and her friends say good-by.  Then the shadows must fall again more heavily than ever, because of their transient lifting.  I almost wished she had indeed gone with her husband, and found myself wondering why he had not asked her to do so when he found what it was that depressed her.  Perhaps he had, and it was she who had held back.  She may have made up her mind to conquer this weakness, and to conquer it where it had originated and necessarily held the strongest sway.  At all events, he was gone and she was here, and I had done nothing as yet to relieve that insidious dread with which she must anticipate a night in this house without his presence.