It seemed to me that there was someone else in the house in the valley, an alien human being who had no business there, but intruded from outside. Though his occupation seemed to be to paint pictures, I was reasonably certain that he had come to spy. I caught only the most fugitive glimpses of him—on occasion a reflection in a mirror or in a windowpane when I was near, but I saw in the north room of the ground floor the evidence of his work—one unfinished canvas on his easel, and several that had been completed.