And take first his two scales of time. As a matter of incontrovertible fact he was living in the year 1920. In the year 1920 a big and handsome and athletic man was living a daily life, presumably somewhere in London. But for him that year was 1910, and continually, day by day and hour by hour, he must be struggling to reconcile those two periods. It could make no difference that he knew that he was living in both years simultaneously. A hundred times a day he might say to himself, "I quite understand; this is both 1910 and 1920; I've got them perfectly clear and separate in my head." But the hundred-and-first time would catch him tripping. He would stumble over some sudden and unexpected trifle. Let me make this clear by means of a small incident that happened to myself. Not long ago I walked into Charbonnel's for a cup of tea, and was passing through the shop on the ground floor and about to mount the stairs when I was politely fetched back. I was told, with a smile that might have been given to a man just returned from Auckland or Mesopotamia, that the upper room had been closed for some time. I had not been in Charbonnel's since the early days of the war, and was looking, in 1920, for a Charbonnel's that had ceased to exist. So Derwent Rose, however much he was on his guard, would once in a while find himself looking for something that no longer existed. Next, there was the question of money--common money, and how much of it he had got. Obviously, and supposing he was to be found, it was no good looking for him in places where he could not possibly afford to be. He would be found in a cheaper place or a more expensive one according to the state of his purse. I had no means of knowing how much money he had withdrawn from the bank. I had never known much about his finances except that sometimes he had been hard-up, at others comparatively "flush," but that he had never, as far as I knew, borrowed. Thus the vulgarest of all considerations had an important bearing on our very first step: Where to look for him?