Thus far she chatted about herself quite freely; but when I tried, even in the vaguest manner, to lead her into discussing the causes of her strangely secluded life, she looked so distressed, and became so suddenly silent, that I naturally refrained from saying another word on that topic.  One conclusion, however, I felt tolerably sure that I had drawn correctly from what she said:  her father’s conduct toward her, though not absolutely blamable or grossly neglectful on any point, had still never been of a nature to make her ardently fond of him.  He performed the ordinary parental duties rigidly and respectably enough; but he had apparently not cared to win all the filial love which his daughter would have bestowed on a more affectionate man.

When, after reflecting on what Alicia had told me, I began to call to mind what I had been able to observe for myself, I found ample materials to excite my curiosity in relation to the doctor, if not my distrust.

I have already described how I heard the clang of the heavy door, on the occasion of my first visit to the red-brick house.  The next day, when the doctor again took leave of me in the hall, I hit on a plan for seeing the door as well as hearing it.  I dawdled on my way out, till I heard the clang again; then pretended to remember some important message which I had forgotten to give to the doctor, and with a look of innocent hurry ran upstairs to overtake him.  The disguised workman ran after me with a shout of “Stop!” I was conveniently deaf to him—­reached the first floor landing—­and arrived at a door which shut off the whole staircase higher up; an iron door, as solid as if it belonged to a banker’s strong-room, and guarded millions of money.  I returned to the hall, inattentive to the servant’s not over-civil remonstrances, and, saying that I would wait till I saw the doctor again, left the house.

The next day two pale-looking men, in artisan costume, came up to the gate at the same time as I did, each carrying a long wooden box under his arm, strongly bound with iron.  I tried to make them talk while we were waiting for admission, but neither of them would go beyond “Yes,” or “No”; and both had, to my eyes, some unmistakably sinister lines in their faces.  The next day the houskeeping cook came to the door—­a buxom old woman with a look and a ready smile, and something in her manner which suggested that she had not begun life quite so respectably as she was now ending it.  She seemed to be decidedly satisfied with my personal appearance; talked to me on indifferent matters with great glibness; but suddenly became silent and diplomatic the moment I looked toward the stair and asked innocently if she had to go up and down them often in the course of the day.  As for the doctor himself he was unapproachable on the subject of the mysterious upper regions.  If I introduced chemistry in general into the conversation he begged me not to spoil his happy holiday hours