For two years Rachel and I had lived in this silent, limited partnership. My home was cool and soundless as the grave, a place in which the mind could stretch its shriveled wings, where everything could be done mechanically and without fear of a sudden jar into disagreeable reality. When of an afternoon I stepped from the hurrying world into the first quiet woods on the way to my home, a great door swung to behind me and another life began, in which Rachel's figure and swarthy, heavy-featured face had long ceased to interfere with my meditation. This night, however, before the meal was served, the kitchen door opened and my housekeeper's inscrutable dull eyes rolled around the walls of the room; then it closed. What had happened? Why on this night had Rachel noticed my arrival? At supper I broke our unspoken compact and addressed her. "Rachel, what made you look in just now? Has anything happened?" The woman made no reply, yet there was evidence in her manner that she was groping for an answer. Presently to a second demand she made a reply that startled me:-- "Heard two of you." So, another ear had detected the steps as well as my own! Then the being, whatever it was, must be in the room, possibly at my elbow; or, seated perchance on that chair before me, was regarding me steadfastly! Except for the excitement bred of a new sensation, it was not a pleasant thought; nevertheless, I pulled a second chair to the table and filled a second plate with food; then, with my eyes fixed on the plate, continued the meal. It was all in vain. Nothing further was seen or heard. This was my first definite encounter with that unseen which I would have called a spirit had I been a spiritualist. But I could not force myself to the gross materialism of calling this invisible existence a spirit, for tangibility was a quality I could not associate with pure spirit, and I had touched it. Having once followed me, it seemed thenceforth to take up quarters in my house, at least for the evening and morning hours of the day, and strange as it was, I soon learned to regard the presence of a third person as an established fact; indeed, I came to believe that in some instances a faint breathing might be detected. Nevertheless I would not leave anything to the possibilities of imagination, but was always experimenting, with a view to prove still more clearly that there was no illusion possible. To this end a brass and steel rod, fitted between the floor and a projection from the wall, was connected with an indicator which moved in a large arc when the slightest touch shook the floor. By this means my ears were reinforced by sight. I also began systematically to conceal from the unknown guest the fact that I suspected its presence; but at last the point was reached where, to protect my own reason, it must be settled whether it was all a series of illusions or a sober truth.