“Supposing,” he argued, “supposing Rainham had given signs of a desire to marry my sister, or my cousin, or any other girl in whom I was interested, or, in short, whom I knew, it would obviously have been my duty, before giving my consent or approval, to find out all about his relations with that girl, that person whom I saw with him in the park—­ah, yes!  Kitty, that was her name.  And, in a way, don’t I owe far more to society in general than I do to any of my immediate friends in particular?  Well, then I ought to know more about Kitty, so as to be prepared in case—­that is, for emergencies....  Why, for all I know, I may have been suspecting Rainham all this time quite unjustly.  I’m sure I hope so.”  Here he shook his head sorrowfully.  “But I’m afraid there’s not much chance of that.  The question remains, how am I to find out anything?  It’s no good asking Rainham; that goes without saying.  It would be equally useless to try Lightmark:  they’re as thick as thieves, and he’s not the sort of man to be pumped very easily.  And yet, if Rainham’s friends are out of the question, what’s to be done?  He hasn’t got any enemies—­that sort of man never has, except himself.  How can I get hold of the girl?  I suppose some people would set a detective to watch Rainham, and so on; but that’s not to be thought of, in this case.”  He stopped close to Cleopatra’s Needle, and frowned abstractedly over the stone parapet, absently following the struggles of a boy who was laboriously working a great, empty lighter across the wide, smoke-coloured river at a narrow angle with the shore.  An idea suggested itself in flattering colours for a moment:  he might pay a visit to the little restaurant or club in Turk Street, the shady place with a foreign name which he had forgotten.  At the expense of a little tact, he might very probably succeed in inducing some of the careless, disreputable young artists who formed the frequentation of the place to talk about Rainham’s amours.  It even occurred to him that at a late hour Kitty herself might be seen there, dancing a can-can with Rainham, or singing songs with a riotous chorus.  But in spite of this prospect, the notion was not sufficiently attractive.  He had not enjoyed his introduction to the eccentric fraternity, on the occasion when he had been fired by Lightmark’s early enthusiasm about the place to request to take him there to dine.  He had felt, almost as much as the men to whom he was introduced, that he had no business there, that he was an outsider; he had even been snubbed.  “And, after all,” he said impatiently, resuming his homeward direction, “though I’ve got enough evidence to damn him twice over in the eyes of any man in the world, I suppose it wouldn’t be enough to convince a woman, if she believed in him.  I must get hold of Kitty—­it’s the only way to arrive at a certainty.”