In a few minutes we were both inside old Jimmy's cosy quarters. His whole bearing seemed to have changed suddenly, and he ran about with alacrity, getting supper ready, and seeming quite like himself again. During the whole evening he kept harping at intervals on the subject of the mysterious voice, but we heard no sound whatever, and I felt more and more certain that the whole thing was due to hallucination on the part of the old man. At eleven o'clock a skiff came up through the lock, and almost immediately afterwards I bade Jimmy good-night and went into the little room he had prepared for me. I went quickly to bed, and, tired after my long pull, despite the originality of the situation, fell fast asleep. Suddenly I awoke--some one was bending over me and calling me by my name. I leapt up, and, not realising where I was for the moment, but with a sort of dim idea that I was engaged in some exposure, instinctively seized the man roughly by the throat. In a moment I remembered everything, and quickly released my grip of poor old Jimmy, who was gurgling and gasping with horror. I burst out laughing at my mistake, and begged his pardon for treating him so roughly. "It is all right, sir," he panted. "I hope I didn't frighten you, but I have heard it again, not five minutes ago." "The deuce you have," I said, striking a match and looking at my watch. It was nearly two o'clock, and before the minute was up I heard distinctly a cry, as if from some great distance, of "Lock, lock, lock!" and then all was silence again. "Did you hear it, sir?" whispered the old man, clutching me by the arm with a trembling hand. "Yes, I heard it," I said. "Don't you be frightened, Jimmy; just wait till I get my clothes on; I am going to see this thing through." "Be careful, sir; for God's sake, be careful," he whispered. "All right," I said, slipping on some things. "Just get me a good strong boat-hook, and don't make too much noise. If this mystery is flesh and blood I'll get to the bottom of it somehow. You stay here; and if I call, come out." I took the thick, short boat-hook which he had brought me and, softly unlatching the door, went out. The moon was now riding high overhead and casting black fantastic shadows across the little white cottage. All my senses were on the keenest alert, my ears were pricked up for the slightest sound. I crept softly to the bridge on the upper gate which was open. I looked up stream and thought I could see some little ripples on the surface of the water as if a swift boat had just passed down, but there was no sign of any craft whatever to be seen. It was intensely still, and no sound broke the silence save the intermittent croaking of some bull-frogs in the dark shadows of the pollards on the further bank. Behind me could also be heard the gurgling twinkle of the overflow through the chinks of the lower gate.