She assented readily, and we struck off up a little footpath, barely traceable, that followed the course of the stream. It was, as she had said, a scant ten minutes before the sound of the sluice broke on our ears, and through a sudden clearing of the woods the dam lay before us, a black sinister sheet of water, covered with masses of floating weed and pond-lilies, and darkened by the trees and underbrush that grew closely down to its edge. An old scow, long past use and sunken low in the water, lay pad-locked to a slimy stump near the shore. Following an old cart-track, we skirted the edge of the dam in the direction of the saw-mill, a dilapidated building with broken roof, that seemed to have stood for many years of disuse. To reach it we had to cross the sluice itself, and Mary Lessing, who was a few paces ahead of me, paused to look down over the single rough handrail that protected one from a misstep. There is something forbidding about a mill-sluice at any time, especially when dissociated, as this was, from the companionable sound of human labour. The sheer depth, the knowledge of the vast imprisoned force behind one, the sound of water gushing here and there between the slimy weed-grown timbers, give always, to me at least, an indefinable sense of the sinister. I leaned my rod against the railing, and we looked down side by side at the black oozing wall below. "I like this place," Mary Lessing said. "There's something queer and creepy about it. I often come here. I suppose they haven't worked the sluice for years." "I doubt if the machinery would move now," I said. "Of course this is never opened. There should be a smaller sluice for the millstream further on." I glanced as I spoke at the clumsy wooden levers near me that controlled the sluice. They looked to be rotting in their place, but as I pushed one, idly, a sudden change in the sound of escaping water below warned me that the machinery was not in such ill repair as it would seem. I exerted my strength to pull the lever back, and my attention was momentarily distracted from the girl beside me. She was leaning out over the hand-rail, and when I turned it was with a sudden cry of warning. "Look out!" I said. "That may not be safe!" I caught her arm instinctively as I spoke, and on the instant the rail bent outward with a slight sound of cracking. In another moment she would have been over the edge. We looked at one another, and Mary laughed, a little nervously on the stillness. Her face had flushed. "I thought that rail was all right," she said rather awkwardly. "Dick walked over here with me not a week ago, and we tested it then to see." "It isn't all right now," I returned sharply. I put my two hands on the rail, giving it a slight wrench outward. It gave easily to my touch, and looking closer, I saw that the surface towards the water had been half cut through. Someone had tampered with it deliberately and within the last few days.