Wilson was greatly disheartened, for he was most anxious to stand well with Mr. Barnes, his chief. Yet in revolving over the occurrences of the last half hour he could not see how he could have prevented the escape of his man, since it was evident that he had intentionally acted in a way to prevent pursuit. If one but knows or suspects that he is being shadowed, the Third Avenue elevated road, with its bridges at Thirty-fourth and Forty-second Streets, offers the most effectual means of eluding the most skilful detective. If Wilson had known anything whatever about the man who had escaped him, he might have been able to guess his destination, and so have caught up with him again by hurrying ahead and meeting him, as he had frequently done when following noted criminals with whose haunts he was acquainted. In this instance he was utterly in the dark, so could do nothing but swear.
If he could not report where Mr. Mitchel had gone, at least he might discover at what time he returned to his hotel, and possibly Mr. Barnes might receive some valuable hint by the lapse of time. With this idea, Wilson returned to the Fifth Avenue Hotel and waited patiently. He telephoned to head-quarters only to hear that Mr. Barnes had gone back to Boston to bring Pettingill to New York. Seven o'clock arrived, and yet his vigil was unrewarded. It suddenly occurred to him that as he had seen Mr. Mitchel purchase tickets for the Casino, that might be a good place to watch, though of course there was no certainty that they were for that night. Upon this meagre hope he hastened up-town and stationed himself where he could keep an eye on all who entered. At ten minutes past eight he was about concluding that his task was useless when a cab stopped, and to his intense satisfaction he saw Mr. Mitchel alight, and then hand out a handsomely-dressed woman. Wilson had prepared himself for this possibility, by purchasing a ticket of admission, so that he followed the couple into the theatre, determined not to lose sight of his man again. The opera over, he found it easy to shadow the two, as the woman declined the proffered cab, perchance because the exhilarating, though cold night air made a walk home inviting. He was, however, somewhat amazed at last to see them enter the very apartment-house on Thirtieth Street to which he had traced Rose Mitchel in the morning. His mind was at once set at ease, for since both of his birds had flown to the same dove-cot, it seemed plain that they were connected. Evidently it was to this house that Mr. Mitchel had gone after eluding him in the morning. At least so argued the astute detective.
Wilson had waited opposite the building perhaps an hour, lulled into abstraction of thought by the silence of the neighborhood, when he was startled by hearing a piercing shriek, loud and long continued, which then died away, and all was still again. Whether it came from the apartment-house or one of the private dwellings next to it, he was in doubt. That it was a woman's cry he felt sure. Was it a cry of pain, or the shriek of nightmare? He could not tell. That solitary, awful cry, disturbing the death-like stillness, seemed uncanny. It made him shiver and draw his cloak closer about him. If it had only been repeated, after he was on the alert, he would have felt better satisfied; but though he listened intently he heard nothing. Ten minutes later, another thing occurred, which attracted his attention. A light in a window on the fifth floor was extinguished. There was certainly nothing suspicious about this, for lights are usually put out when one retires. He noticed it because it was the only light which showed from any of the windows during his vigil. Whilst he was thinking of this, the door opposite opened and a man emerged. Judging it to be Mr. Mitchel, he hastily followed. That there might certainly be no mistake, Wilson walked rapidly enough to reach the Avenue corner ahead of the man, when he crossed, so timing himself that he passed in front of the other just as they both reached the street lamp. Taking a quick, but thorough look, Wilson saw that it was not Mr. Mitchel, so abandoned the pursuit, going back quickly towards the apartment-house. He had proceeded but a few paces, when he met Mr. Mitchel coming rapidly towards him. Breathing a sigh of relief, he passed, then crossed the street, and with his usual skill readily kept Mr. Mitchel in sight till he entered the Fifth Avenue Hotel. Wilson saw him take his key and go up-stairs, so that he felt that his vigil was over for that night. Looking at his watch he noted that it was just one o'clock. Going into the reading-room he wrote a report of the day's occurrences and then calling a messenger, sent it to head-quarters addressed to Mr. Barnes. This done he felt entitled to hurry home for a short sleep—short, because he knew it would be his duty to be on the watch again the next day, and until he received further instructions from Mr. Barnes.
Mr. Barnes had immediately after his arrival obtained the requisition papers for which he had telegraphed, and which he found awaiting him. With these he had returned to Boston the same day, and obtaining his prisoner succeeded in catching the midnight train once more, arriving in New York with the loss of but a single day from the new case which so absorbed all his interest.
Thus the morning after that on which the jewel robbery had been discovered he entered his offices quite early, having delivered his prisoner at police head-quarters.
When he read Wilson's letter, the only sign which he gave of dissatisfaction was a nervous pull at one corner of his moustache. He read the paper through three times, then tore it carefully into tiny pieces, doing it so accurately that they were all nearly of the same size and shape. Any one who should attempt to piece together a note which Mr. Barnes had thus destroyed, would have a task. Standing by the window he tossed them high in the air and saw them scattered by the wind.
At half past eight o'clock he stood before the apartment-house in East Thirtieth Street. The janitor was sweeping from the pavement a light snow which had fallen in the early hours of the morning.
Mr. Barnes without speaking to the man walked into the vestibule and scanned the names over the letter-boxes. None of them contained the one which he sought, but there was no card in No. 5. Recalling that in Wilson's report a light had disappeared from a window on the fifth floor, he knew that it could not be unoccupied. To get in, he resorted to a trick often practised by sneak thieves. He rang the bell of No. 1, and when the door silently swung open he walked in, apologizing to the servant on the first landing for having "rung the wrong bell," and proceeded up to the fifth floor. Here he rang the bell of the private hall belonging to that special apartment. He could have rung the lower bell of this apartment at the outset, but he wished to make it impossible for anyone to leave after his signal announced visitors. He stood several minutes and heard no sound from within. A second pull at the bell produced no better results. Taking