“She may have been waiting for evening,” he said to himself. “She would know, at least, that there is less risk than in daylight. Or she may have an appointment for the evening, as Nick suspects.” Chick then had not long to wait. The light in the upper room suddenly vanished. Presently the side door of the house was opened, and in the stream of light from the hall the dainty figure of the girl appeared for a moment, only to be lost briefly in the gloom of the vestibule after she closed the door. Chick then saw her trip lightly down the steps and out to the street, clad in a trim jacket and a hat that only partly hid her abundance of yellow hair. After turning the first corner, however, stealthily followed by the detective, Minerva stopped short and took a voluminous veil from her pocket, which she carefully tied over her hat and hair, then drew it down until it completely hid her girlish face. “That does settle it,” thought Chick, constantly watching her. “She’s off on some evil mission. Nick sized her up correctly, all right. She evidently has no fear of being followed, which will make it all the easier for me. By Jove, this seems like chasing a fairy. She can’t weigh more than ninety pounds.” Minerva had started off again, with the detective after her. Ten minutes brought her to a subway station, where she took a downtown train. Alighting at Forty-second Street, she walked briskly away and soon brought up opposite a restaurant and concert hall having a somewhat unenviable reputation. There she paused in a doorway to gaze over at the lighted windows. “She’s looking for some one, or waiting for some one to show up,” thought Chick, after briefly watching her. “I may get a line on the party before her, by Jove, in case he already has arrived. She cannot see from over there.” Minerva still was lingering in the doorway. Leaving the corner on which he had paused to watch her, Chick sauntered into the place and bought a drink at the bar. Beyond the barroom, through a broad entrance adorned with potted palms, was a large concert hall filled with numerous tables and with curtained booths flanking the side walls. Patrons of the place were seated at many of the tables, eating, drinking, and smoking. A score of waiters were hurrying to and fro. In the rear of the hall an orchestra was playing popular airs. The noise and stir were incessant. Gazing into the broad mirror back of the bar, Chick suddenly made a discovery--a woman seated alone in one of the nearest booths. The curtains were partly drawn, and Chick would not have discovered her save for the angle afforded by the mirror.