With these the woman was fumbling with hesitating, awkward fingers. "Cat--dog? I don't--I don't understand, Tom--I see, Tom,--these are the pictures of cats and dogs. I'm blind, and stupid, and slow. I ought to have seen at once what they were?--I know I ought. But--be patient with me, Tom. Which one?--This one? Yes, I see--this one. It's--it's--yes, Tom, it's a dog's head, I see it is.--What am I to do with it? Press?--Yes, Tom, I am pressing.--Press harder? Yes, I'll--I'll try; but I'm--I'm not very strong, and I can't press much harder. Have mercy!--have mercy, Tom! Say--say you forgive me--forgive me! but I--I can't press harder, Tom--I can't!" She could not--so much was plain. Even as the words were passing from her lips, she relinquished pressing altogether. Uttering a little throbbing cry, she turned away from the wall, throwing up her arms with a gesture of entreaty, and sinking on to the floor, she lay there still. As she dropped, that gentle, mocking laugh rang through the startled room. CHAPTER XVIII MADGE APPLIES MORE STRENGTH Was it imagination? Or was it fact? Did some one or something really pass from the room, causing in going a little current of air? With startled faces each put to the other an unspoken query. Which none answered. The woman lay there, motionless, her exceeding stillness seeming accentuated by the sudden silence which filled the room. Bruce Graham, moving forward, took her up in his arms, as if she were but a feather's weight. His knife fell from her nerveless fingers, tumbling to the floor with startling clatter. Madge picked it up. Her voice rang out with clarion clearness--the voice of a woman whose nerves were tense as fiddle-strings. "I'll see if I cannot press harder. This mystery must be solved to-night--before some of us go mad; if pressing will do it, it shall soon be done--if there's strength in me at all." There was strength in her--and not a little. She went on her knees where the woman had been; and, as she had done, fumbled with her fingers where the paper had been scraped from the wall, peering closely at it, as she did so. "A dog's head, is it?--it doesn't look as if it were a dog's head to me, and that's not because I'm stupid. It's to be pressed, is it?--Well, if pressing will do it, here's for pressing!" She exerted all her force against the point to which the woman had been directed. "It gives! It gives!--something gives beneath my thumb: it's the knob of a spring or something--I'm sure of it." Turning, she looked up at Graham with flaming cheeks and flashing eyes. "The spring is sure to be rusty. It will need all your strength. Try it again." She tried again. "It does give--it does! But whatever it is supposed to open is not likely to act now that the wall has been repapered. Some one go and fetch the hammer and the chisel from downstairs--we'll try another way."