The next hour passed very slowly. I walked up and down; at one time absorbed in my own thoughts; at another, engaged in watching the gradual diminution in the number of foot passengers who passed me as the night advanced. The City (as it is called) is the most populous part of London in the daytime; but at night, when it ceases to be the center of commerce, its busy population melts away, and the empty streets assume the appearance of a remote and deserted quarter of the metropolis. As the half hour after ten struck--then the quarter to eleven--then the hour--the pavement steadily became more and more deserted. I could count the foot passengers now by twos and threes; and I could see the places of public refreshment within my view beginning already to close for the night. I looked at the clock; it pointed to ten minutes past eleven. At that hour, could I hope to meet Mrs. Van Brandt alone in the public street? The more I thought of it, the less likely such an event seemed to be. The more reasonable probability was that I might meet her once more, accompanied by some friend--perhaps under the escort of Van Brandt himself. I wondered whether I should preserve my self-control, in the presence of that man, for the second time. While my thoughts were still pursuing this direction, my attention was recalled to passing events by a sad little voice, putting a strange little question, close at my side. "If you please, sir, do you know where I can find a chemist's shop open at this time of night?" I looked round, and discovered a poorly clad little boy, with a basket over his arm, and a morsel of paper in his hand. "The chemists' shops are all shut," I said. "If you want any medicine, you must ring the night-bell." "I dursn't do it, sir," replied the small stranger. "I am such a little boy, I'm afraid of their beating me if I ring them up out of their beds, without somebody to speak for me." The little creature looked at me under the street lamp with such a forlorn experience of being beaten for trifling offenses in his face, that it was impossible to resist the impulse to help him. "Is it a serious case of illness?" I asked. "I don't know, sir." "Have you got a doctor's prescription?" He held out his morsel of paper. "I have got this," he said. I took the paper from him, and looked at it. It was an ordinary prescription for a tonic mixture. I looked first at the doctor's signature; it was the name of a perfectly obscure person in the profession. Below it was written the name of the patient for whom the medicine had been prescribed. I started as I read it. The name was "Mrs. Brand." The idea instantly struck me that this (so far as sound went, at any rate) was the English equivalent of Van Brandt. "Do you know the lady who sent you for the medicine?" I asked.