Suddenly I heard a soft faint moan, which seemed to come from behind the locked door at the back of the shop. On the impulse of the moment and with rather a grue--as the Scotch call it, for the sound was sinister and unexpected--I sprang forward and gripped the handle of the door. To my surprise, the moment I twisted it the door opened at once, and yet I swear that it was locked when I had last tried it. I looked into a dark room, and could see faintly to the right a barred window, which showed against the fast darkening evening sky. No further moan could I hear, although I listened with all my ears. Wondering if I had been mistaken, and yet uneasy about the now unlocked door, I stepped into the back room, holding on to the inside handle. As it afterwards turned out the floor of the room was lower than that of the shop, and reached by three shallow steps. I therefore stumbled, and pulling the door after me with some violence, so that it clicked to, I fell sprawling, and bruised my elbow somewhat painfully. Still I heard no sound, but seated on the floor to collect my senses--somewhat dazed by the unexpected fall--I put out my hand to explore the darkness. It fell on soft flesh, warm to the touch, and on rough tangled hair. Thoroughly startled, and with every excuse, I withdrew my hand, and fumbled in my pockets for a match, regretting that I had not brought one of the lamps. I had half a mind to go out and fetch it, but my curiosity was so great and--to be plain--my nerves were so unstrung, that I struck the lucifer, anxious to know the best or the worst at once. As the pale tiny light grew stronger, I beheld the form of a woman lying on the stone floor, face uppermost. And that face--I shuddered as I looked, for it was distorted into an expression of pain, with a twisted mouth and glassy, expressionless eyes. Framed in loose masses of iron-grey hair, it glimmered milky white, and bore the stamp of death on every feature. The woman was dead, and judging from the moan I had heard and the still warm flesh, she had just died. While I stared the match-light went out, and I fancied that I heard a faint click. I lighted another match hastily looking towards the door leading to the shop. It was still closed, and I turned again to gaze at the dead woman, who was old, ill-favoured, and eminently plebeian. At that moment I heard the buzz of the Rippler. At once, in astonishment and alarm, I sprang towards the door. It was locked, and I was a prisoner. While I was still trying to grasp this astounding fact, the drone of my motor car died away in the distance. CHAPTER II. THE BEGINNING OF A MYSTERY