My visit was well timed, and I had not long to wait. The Misses Hansons’ Mr Gilbertson passed before my view, and I had not the slightest hesitation in judging him to be also Miss Rankin’s Mr Gilbertson. I was sorry for this, for he looked so frank and honest that anybody might have trusted him; and it is sad to have one’s ideals shattered, even if one be a detective, and, as such, already somewhat inured to the depressing influence of treacherous natures. But my task was by no means finished. I had only seen and heard enough to corroborate the truth of Miss Cloudy’s statements, and there was too much at stake to permit any chance of blundering to survive. So when Mr Gilbertson went upstairs, I terminated my visit to the old lady, and stationed myself where he could not emerge from the house without being seen by me. I had to wait above an hour, but it was not at all cold, and I was rewarded by seeing the gentleman come forth with one of the sisters, who certainly looked quite worthy of a man’s love. The couple walked slowly towards Hammersmith-road, followed unobtrusively by myself, who, in the gathering dusk, noticed that they appeared to be waiting for some one, as they sauntered backwards and forwards for awhile in the vicinity of St. Mary Abbott’s-terrace. Presently they were joined by another girl, who came out of a neighbouring house, carrying a music roll in her hand, and who was sufficiently like Mr Gilbertson’s companion to make me conclude that she was her sister. Then the three retraced their step homeward, and I had no difficulty in deciding that the music teacher was the sister to whom Mr Gilbertson was supposed to be engaged. I was surprised at the openness with which he carried on his clandestine connection, for he seemed not to care who noticed him, and it was certainly running an apparent risk to show himself out of doors with Miss Rankin’s rival. I will own to being very tired before I got to bed that night. But I was thoroughly satisfied, for I had traversed a great deal of ground, and learnt a great many important particulars of the case I was investigating. Next morning at eleven o’clock I called to see Miss Rankin at her sumptuous flat in Albert-gate Mansions, and induced her to write the following note to her fiancée: - “I cannot see you before half-past eight this evening. But as it is absolutely necessary that I should see you then, I must ask you to put your work on one side for once, and be here at the time indicated without fail. “Iris.” At eight-thirty that evening, having donned orthodox evening wear, I was sitting with Miss Rankin, waiting for the development of my little plot. The poor girl looked very pale, and I could see that the great anxiety was almost killing her. But I knew that it could not last much longer, and a little thrill of excitement ran through me when Miss Hanson and Mr Gilbertson were announced.