The vague "motion" was now positive and definite--an appearance of torsional movement, or of whirling; much like a minute yet intense whirlwind or waterspout, or a huddle of autumn leaves dancing circularly in an eddy of wind along a level lawn. It was, like the earth's, a double motion--around and around, and at the same time _inward_, as if the whorls poured themselves endlessly toward some point inside the glass. Fascinated, yet realizing that the thing must be an illusion, I grasped an impression of quite distinct _suction_, and thought of Robert's embarrassed explanation: "_I felt as though it were pulling my finger into it._" A kind of slight chill ran suddenly up and down my backbone. There was something here distinctly worth looking into. And as the idea of investigation came to me, I recalled the rather wistful expression of Robert Grandison when the gong called him to class. I remembered how he had looked back over his shoulder as he walked obediently out into the hallway, and resolved that he should be included in whatever analysis I might make of this little mystery. * * * * * Exciting events connected with that same Robert, however, were soon to chase all thoughts of the mirror from my consciousness for a time. I was away all that afternoon, and did not return to the school until the five-fifteen "Call-over"--a general assembly at which the boys' attendance was compulsory. Dropping in at this function with the idea of picking Robert up for a session with the mirror, I was astonished and pained to find him absent--a very unusual and unaccountable thing in his case. That evening Browne told me that the boy had actually disappeared, a search in his room, in the gymnasium, and in all other accustomed places being unavailing, though all his belongings--including his outdoor clothing--were in their proper places. He had not been encountered on the ice or with any of the hiking groups that afternoon, and telephone calls to all the school-catering merchants of the neighborhood were in vain. There was, in short, no record of his having been seen since the end of the lesson periods at two-fifteen; when he had turned up the stairs toward his room in Dormitory Number Three. When the disappearance was fully realized, the resulting sensation was tremendous throughout the school. Browne, as headmaster, had to bear the brunt of it; and such an unprecedented occurrence in his well-regulated, highly-organized institution left him quite bewildered. It was learned that Robert had not run away to his home in western Pennsylvania, nor did any of the searching-parties of boys and masters find any trace of him in the snowy countryside around the school. So far as could be seen, he had simply vanished.