uddenly the figure of a man stepped out before us. It was too dark to see his face, but his voice had a familiar sound as he said:

"It's all right. He's there. I saw him go in a half-hour ago."

"Very good. My man, Sweetwater," explained Mr. Gryce, turning for an instant towards me; then, in hurried tones to the other, "Do you know on which floor he is to be found; and whether the man at the bar suspects what's up?"

"If he does, he's pretty quiet about it. All looks natural inside. But you can't tell what whispers have gone about. As for him, he's chosen his place with his usual indifference to consequences. He's in one of the attic rooms, sir, well back, and can be reached from the outside by means of a shed that slopes up almost to the window-ledge. If he wanted to escape, he could easily do so by a drop of only four feet. But I have left a man on watch there and our young gentleman would fall into arms that wouldn't let him go in a hurry. Will you come around that way? There's a light in the window and there's neither curtain nor shade to hinder a man's looking in. If you wish, I can crawl up on the roof I spoke of and take a peep at our doves before we venture upon disturbing them."

"It can do no harm," rejoined the older detective; "and if the girl is where she can be seen, this gentleman can go up afterwards and identify her. It will mean surer and quieter work than approaching them by the stairway. The house is full, I suppose?"

"Chuck." And with this characteristic word Sweetwater melted from before us as if he had been caught up in one of the swirls of wind and rain that ever and anon swept through the alley, dashing our faces with wet and making our feet unsteady on the slippery pavement.

I began to feel strange and unlike myself. The night, the storm, the uncongenial place, our more than uncongenial errand, were having their effect, lending to that dark entrance into one of the worst corners of our great city a sense of mysterious awe which has caused it to remain in my memory as something quite out of the ordinary experiences of life. It was not a long alley, and we soon reached the light I have mentioned. We could hear voices now, loud voices raised one moment in contention, the next in drunken cheer; and, thrilling through it all, a woman's tones singing some bewildering melody. It was not the voice of Mille-fleurs. I could never have mistaken that—but it was a young voice, and did not lack sweetness in the low notes. As I was listening to it, something flew flapping into my face. It was a piece of damp paper peeled from some billboard by a wandering gust and sent scurrying through the air. I tore it away from my eyes, drawing a deep breath like a person suddenly released from suffocation; but I shall not soon forget the effect of that cold slap in the face at the moment when my every nerve was on tension. Mr. Gryce, who had seen nothing,—it was hardly possible to see in the deluge which now swept down upon us,—gave me a pull which drew me from before the swinging door I was unconsciously making for, into a corner where I found myself more or less shielded from the wind if not from the rain. The alley had an L, and leading down from this L was a narrow passage, within which we now stood, surrounded by reeking walls and facing (whenever the fury of the storm abated sufficiently for us to look up) an opening into what might be called a labyrinth of back-yards. As I was bracing myself to meet all alarms, real or imaginary, associated with this noisome place, I beheld a sudden figure emerge from the opening and hastily approach us. It was Sweetwater again. He had just descended from his clamber over the roofs, where he seemed to be as much at home as a cat.

"Lucky that it rains so," he panted; "keeps the kids in. Otherwise some of us would have been spotted long ago. There are about fifty of them in this one house." Then I heard him whisper in the ear that was necessarily very near mine:

"It's all right up there. I can see his figure plainly. He's sitting with his back to the window, but there's no mistaking Leighton Gillespie. He's in dinner dress, just as he came from his own table in Fifth Avenue. The girl——"

"Well, what of the girl?"