Drew rubbed the rear glass of the taxi. He pressed his nose against this. A blurred form, almost obliterated by falling snow, showed where the operative was guarding the mansion. Delaney, who was watching out through another window, suddenly clutched Drew by the arm. "Look!" he exclaimed. "Look, Chief! Over toward the big house!" The Detective drew back from his study of Harrigan. He turned on the seat and followed Delaney's pointing finger. He clamped his jaw shut with a click of strong teeth. "Somebody's coming out of Stockbridge's," said the operative. "Quek!" signaled Drew. "Watch, closely," he added in a whisper. A girl came through the doorway and opened the iron-grilled gates. She paused and glanced north and south through the curtain of down-falling snow. She turned with resolution and hurried along the east side of the Avenue. She was at the corner opposite the taxi, when Drew reached and opened the door with sly fingers. "Tail her," he ordered. "Right after her, Delaney. I'd know that little lady in a million." "Who is she, Chief?" "Loris Stockbridge!" "Sure?" "Yes! Right after her! There--she turned east. See her white spats? See her furs? Some queen to be out a night like this. Don't let her get too far ahead of you. That's right, Delaney!" The operative sprang to the curb. He rounded the hood of the taxi. He slouched along the pavement to the corner, waited for the fraction of a minute until a limousine passed, then hurried over the Avenue. He disappeared into the canyon whose walls were towering apartments and whose end was marked by a row of soft arcs across which, snow falling from housetops, sparkled in the night like diamonds beyond price. The Avenue churned with returning theater-parties and night-hawk cabs. The roar of the city came to the waiting Detective's ears like a giant turning in his first sleep. The sifting snow sanded against the windows of the taxi. The purring motor missed sparking now and then. It shook the cab as it resumed its revolving with a sputter and a cough in the muffler. The driver huddled deeper in his sheep-skin coat collar. He snored in synchronism with the engine. Drew rubbed the glass before him and studied the aspect with close-lidded intentness. He marked the shut gates of the Mansion down the Avenue. He saw that the lights from the inner globes had been extinguished. He counted the staring windows. His eyes lowered to the soft rose-glow which streamed out through the shut blinds of the library. Snow was on the slats and sills. A swift crunch of heavy shoes at the side of the taxi--the turning of the door-lock--the burly form in black that climbed in, announced Delaney. "All right, Chief!" he said somewhat out of breath. "All right--move over. Here she comes back!"