"All right, sir," replied the man. "I'll be wary, you bet!" and we climbed to the first floor, the rooms of which, to our surprise, were all empty, devoid of any furniture save two or three broken chairs. In one room was a cupboard, which, however, was locked. Again we turned to the stairs, Edwards and his companion ascending each stair slowly and trying the one higher with their hands. They were covered with new carpet of art green, different to the first flight, which were covered in red. When a little more than half-way up to the top landing, Edwards suddenly exclaimed,-- "Here it is, sir!" and instantly we ascended to his side. Kneeling on the stairs, he pressed his hands on the step above, whereupon that portion of the stairway up to the landing swung forward upon a hinge, disclosing a black abyss beneath. I looked into it and shuddered. Even Pickering himself could not restrain an expression of surprise and horror when he realised how cunningly planned was that death-trap. The first six stairs from the top seemed to hang upon hinges from the landing. Therefore with the weight of a person upon them they would fall forward and pitch the unfortunate victim backwards before he could grasp the handrail, causing him to fall into the pit below. "Well," remarked Pickering, amazed, as he pushed open the stairs and peered into the dark blackness below, "of all the devilish contrivances I've ever seen in my twenty-one years' experience in London, this is one of the most simple and yet the most ingenious and most fatal?" "No doubt there's a secret way to render the stairs secure," I remarked. "No doubt, but as we don't know it, Edwards, one of you had better go down and get something to lay over the stairs--a piece of board, a table--anything that's long enough. We don't want to be pitched down there ourselves." "No, sir," remarked Edwards' companion, whose name was Marvin. "I wouldn't like to be, for one. But I daresay lots of 'em have gone down there at times." "Most probably," snapped the inspector, dismissing the man at once to get the board. "Bring up the jemmy as well," he added, over the banisters. "We may want it." A few minutes later the two men brought up a long oak settle from the hall, and bridging the fatal gulf, held it in position, while we passed over, not, however, without difficulty, as the incline was so great. Then when we were over we held it while they also scrambled up. To the left was a closed door--the room from which had come the sound of Eric's voice on that fatal night. I recognised it in a moment, for it was pale green, picked out in a darker shade.