Willing to humour him, I suffered him to stroll up the platform at my side. I held out my hand to him when we reached a hansom. "Your address?" "I said I would give you my address in the cab." Leaning towards me, he spoke in that curious tone which had impressed me so unpleasantly in the railway carriage. "Get into the cab, man; I travelled from Brighton in the next compartment to yours." I was foolish. I ought, even at the eleventh hour, to have addressed myself to an official, to have made a clean breast of it, to have told him of the accident, the unavoidable accident, which had happened on the line. I know that now too well. I knew it, dimly, then. But, at the moment, I was weak. The fellow's manner increased my state of mental confusion. In a sense, his words overwhelmed me. I yielded to him. I got into the cab. He placed himself at my side. "Where shall I tell the man to drive?" he asked. "Anywhere." "Piccadilly Circus!" he shouted. The cab was off. We sat in silence, I in a state of mind which I should find some difficulty in making plain. I will not attempt it. I will only say that I should have dearly liked to have taken my friend, the stranger, by the scuff of his neck and to have thrown him out into the street. I did not dare. When we were clear of the traffic I asked him, in a voice which I scarcely knew to be my own, it was so husky and dry-- "What did you mean by saying that you travelled from Brighton in the next compartment to mine?" "Mean? My dear sir, I meant what I said. It was a coincidence--nothing more." He spoke lightly; impudently even. I felt incapable of pressing him for a more precise explanation. He added, as a sort of afterthought, "I'm a detective." I turned to him with a start. "A detective?" He pretended to be surprised by my surprise. "What's the matter, my dear sir?" He paused. Then, with a sneer, "I'm not that sort. I'm the respectable sort. I'm a private detective, sir. I make delicate inquiries for persons of position and of means." He emphasised "means." "Have you a cigar?" "I gave him one; he proceeded to light it. I was conscious that, since I had admitted him to a share of the cab, a change had taken place in his bearing. It was not only familiar, it was positively brutal. Yet, strange though it may appear--and I would point out that nothing is so common as that sort of wisdom which enables us to point out the folly of each other's behaviour--I found myself unable to resent it. "I've been down to Brighton on business; to make inquiries about a woman." "A woman?" "A woman who is missing--women are missing now and then--Louise O'Donnel. I suppose you never happen to have heard the name?" "Louise O'Donnel?" I wondered what he meant; there was meaning in his tone. Indeed, every word he uttered, every gesture he made, seemed pregnant with meaning. The more I saw of him, the more uncomfortable I became. "I do not remember to have heard the name Louise O'Donnel."