The professor's sense of direction was marvelous. Having reclimbed the shed which blocked the entrance to this concealed pit, he made practically a straight line for the place at which we had entered the wood from the road. "I daresay one would be allowed to see over the house, but perhaps it is as well not to ask," he said. "We can do that later. I'm tired, Wigan; but it was safer not to keep the carriage." Try as I would, I could get no explanation out of him either that night or next day. He was always as secret as the grave until he had proved his theory, and then he seemed anxious to forget the whole affair, and shrank from publicity. That is how it came about that I obtained credit which I did not deserve. "We go there again this evening," he said after lunch next day; "so a restful afternoon will suit us." It was getting dark when we set out, and again Quarles's unerring sense of locality astonished me. He led the way without hesitation. This time he took more precaution not to make a sound when climbing over the shed into the narrow path. "I think we are first, but great care is necessary," he whispered. We crept forward and concealed ourselves among the scrub vegetation which grew in that part of the pit which was open to the sky. It was dark, the long shed barely discernible, but the professor was particular about our position. "We may have to creep a little nearer presently," he whispered. "From here we can do so. Silence, Wigan, and don't be astonished at anything." The waiting seemed long. Moonlight was presently above us, throwing the cave part of the pit into greater shadow than ever. I cannot attempt to say how long we had waited in utter silence when Quarles touched my arm. Someone was coming, and with no particular stealth. Whoever it was seemed quite satisfied that the night was empty of danger. I heard footsteps on the raised floor of the shed--a man's step, and only one man's. I heard him moving about for some time. I think he came down the ladder once and went up again. Then there was a light and sudden tiny flames. In the dark he had evidently got fuel, and had started a fire on the stone slab. As the flames brightened I watched his restless figure. He was not a young man. I caught a glimpse of white hair, but he took no position in which I could see his face clearly. He was short, thick-set, and quick in his movements. From somewhere at the back of the shed he pushed forward a block of wood, and, standing on this, he fixed something to the short chain I had noted yesterday. When he got down again I saw that a bundle was suspended over the fire, not a pot, and it was too high for the flames or much of the heat to reach it, only the smoke curled about it. Then the man moved the wooden block to the side of the fire and sat down facing us, the flickering flames throwing a red glow over him. "Wigan, do you see?" whispered Quarles. "Not clearly." "We'll go nearer. Carefully."