What was Mrs. Packard’s secret trouble?

Why were people afraid to remain in this house?

Why did the old woman next door show such interest in the new member of her neighbor’s household?

Would a single answer cover all?  Was there but one cause for each and every one of these peculiarities?  Probably, and it was my duty to ferret out this cause.  But how should I begin?  I remembered what I had read about detectives and their methods, but the help I thus received was small.  Subtler methods were demanded here and subtler methods I must find.  Meantime, I would hope for another talk with Mayor Packard.  He might clear up some of this fog.  At least, I should like to give him the opportunity.  But I saw no way of reaching him at present.  Even Mrs. Packard did not feel at liberty to disturb him in his study.  I must wait for his reappearance, and in the meantime divert myself as best I could.  I caught up a magazine, but speedily dropped it to cast a quick glance around the room.  Had I heard anything?  No.  The house was perfectly still, save for the sound of conversation in the drawing-room.  Yet I found it hard to keep my eyes upon the page.  Quite without my volition they flew, first to one corner, then to another.  The room was light, there were no shadowy nooks in it, yet I felt an irresistible desire to peer into every place not directly under my eye.  I knew it to be folly, and, after succumbing to the temptation of taking a sly look behind a certain tall screen, I resolutely set myself to curb my restlessness and to peruse in good earnest the article I had begun.  To make sure of myself, I articulated each word aloud, and to my exceeding satisfaction had reached the second column when I found my voice trailing off into silence, and every sense alarmingly alert.  Yet there was nothing, absolutely nothing in this well-lighted, cozy family-room to awaken fear.  I was sure of this the next minute, and felt correspondingly irritated with myself and deeply humiliated.  That my nerves should play me such a trick at the very outset of my business in this house!  That I could not be left alone, with life in every part of the house, and the sound of the piano and cheerful talking just across the hall, without the sense of the morbid and unearthly entering my matter-of-fact brain!

Uttering an ejaculation of contempt, I reseated myself.  The impulse came again to look behind me, but I mastered it this time without too great an effort.  I already knew every feature of the room:  its old-fashioned mantel, large round center-table, its couches and chairs, and why should I waste my attention again upon them?

“Is there anything you wish, Miss?” asked a voice directly over my shoulder.

I wheeled about with a start.  I had heard no one approach; it was not sound which had disturbed me.

“The library bell rang,” continued the voice.  “Is it ice-water you want?”