On the fifth and sixth days Sir John did not come to the City, but he was in his office on the seventh. The door between his room and mine was closed. Shortly after ten o'clock I heard a cry in his room, followed by a heavy fall. I opened the door, and saw Sir John lying face downwards on the floor. Hastening towards him, I felt for the first time the deadly effect of the deoxygenized atmosphere, and before I reached him I fell first on one knee and then headlong. I realized that my senses were leaving me, and instinctively crawled back to my own room, where the oppression was at once lifted, and I stood again upon my feet, gasping. I closed the door of Sir John's room, thinking it filled with poisonous fumes, as, indeed, it was. I called loudly for help, but there was no answer. On opening the door to the main office I met again what I thought was the noxious vapor. Speedily as I closed the door, I was impressed by the intense silence of the usually busy office, and saw that some of the clerks were motionless on the floor, and others sat with their heads on their desks as if asleep. Even at this awful moment I did not realize that what I saw was common to all London, and not, as I imagined, a local disaster, caused by the breaking of some carboys in our cellar. (It was filled with chemicals of every kind, of whose properties I was ignorant, dealing as I did with the accountant, and not the scientific side of our business.) I opened the only window in my room, and again shouted for help. The street was silent and dark in the ominously still fog, and what now froze me with horror was meeting the same deadly, stifling atmosphere that was in the rooms. In falling I brought down the window, and shut out the poisonous air. Again I revived, and slowly the true state of things began to dawn upon me. I was in an oasis of oxygen. I at once surmised that the machine on my shelf was responsible for the existence of this oasis in a vast desert of deadly gas. I took down the American's machine, fearful in moving it that I might stop its working. Taking the mouthpiece between my lips I again entered Sir John's room, this time without feeling any ill effects. My poor master was long beyond human help. There was evidently no one alive in the building except myself. Out in the street all was silent and dark. The gas was extinguished, but here and there in shops the incandescent lights were still weirdly burning, depending, as they did, on accumulators, and not on direct engine power. I turned automatically towards Cannon Street Station, knowing my way to it even if blindfolded, stumbling over bodies prone on the pavement, and in crossing the street I ran against a motionless 'bus, spectral in the fog, with dead horses lying in front, and their reins dangling from the nerveless hand of a dead driver. The ghostlike passengers, equally silent, sat bolt upright, or hung over the edge boards in attitudes horribly grotesque.