Mr. Gryce and Miss Butterworth stepped at once into the light, and surveyed each other with a look of marked discouragement. Then the latter, with a sudden gleam of enthusiasm, cried quickly: "Turn on another color, and let us see what will happen. I have an idea it will fetch the old man down again." Mr. Gryce's brows went up. "Do you think he can see through the floor?" But he touched a button, and a rich blue took the place of the violet. Nothing happened. Miss Butterworth looked disturbed. "I have confidence in your theories," began Mr. Gryce, "but when they imply the possibility of this man seeing through blank walls and obeying signals which can have no signification to any one on the floor above----" "Hark!" she cried, holding up one finger with a triumphant air. The old man's steps could be heard descending. This time he approached with considerable feebleness, passed slowly into the study, advanced to the table, and reached out his hands as if to lift something which he expected to find there. Seeing nothing, he glanced in astonishment up at the book shelves and then back to the table, shook his head, and suddenly collapsing, sank in a doze on the nearest chair. Miss Butterworth drew a long breath, eyed Mr. Gryce with some curiosity, and then triumphantly exclaimed: "Can you read the meaning of all that? I think I can. Don't you see that he came expecting to find a pile of books on the table which it was probably his business to restore to their shelves?" "But how can he know what light is burning here? You can see for yourself that there is no possible communication between this room and the one in which he has always been found by any one going above." Miss Butterworth's manner showed a hesitation that was almost naive. She smiled, and there was apology in her smile, though none in her voice, as she remarked with odd breaks: "When I went upstairs--you know I went upstairs when I was here before--I saw a little thing--a very little thing--which you doubtless observed yourself and which may explain, though I do not know how, why Bartow can perceive these lights from the floor above." "I shall be very glad to hear about it, madam. I thought I had thoroughly searched those rooms----" "And the halls?" "And the halls; and that nothing in them could have escaped my eyes. But if you have a more patient vision than myself----" "Or make it my business to look lower----" "How?" "To look lower; to look on the floor, say." "On the floor?" "The floor sometimes reveals much: shows where a person steps the oftenest, and, therefore, where he has the most business. You must have noticed how marred the woodwork is at the edge of the carpeting on that little landing above." "In the round of the staircase?" "Yes."