"'Good-night,' said our reporter, and turned to go.
"But now it was his turn to linger. Something, in the room which he had not before observed attracted him. It was a simple article enough, a red silk handkerchief which might be worn around the neck.
"Then he left the room. As he descended the stairs he heard the key turned in the door of Constance's room.
"He did not call a cab when he reached the street; he had subject for thought, and like most men he could reflect with greater freedom and ease when his limbs were in motion.
"A red silk handkerchief--merely that. Why should it have made so strong an impression upon him? The explanation might be far-fetched, but since he had pledged himself to the elucidation of the mystery of M. Felix, he had become microscopical in his observation of trifles which might by some remote possibility have a bearing upon it. On the night of the death of M. Felix a man was seen escaping from the house in Gerard Street in which M. Felix lived; and this man wore round his neck a red scarf. It was this coincidence which now occupied his thoughts. The possession of a red silk scarf was common enough; thousands of persons in London could produce such an article, and shop windows abounded with them; but this particular scarf, in connection with the exciting incidents of the night, and in its indirect relation to the advertisement from the _Evening Moon_, which Constance's mother had preserved with such care, suddenly assumed immense importance in the eyes of our reporter. His thoughts wandered to the scene on the Thames Embankment, and he felt himself becoming morbidly anxious to know what it was that Constance's mother had thrown into the river. That it had some connection with the mystery upon which he was engaged he had not the least doubt. Would its discovery, by throwing direct suspicion upon Constance's mother, assist or retard the progress of his mission? To-morrow would show, and he must await the event with patience. One reflection afforded him infinite satisfaction; his hand, and his alone, of all the millions of persons who had no absolute direct interest in it, was on the pulse of the mystery, and every step he took strengthened him in his resolution to run it to earth without the aid of the officials of Scotland Yard."