“Stop right here,” Dave ordered. “I’ll be back soon.”

He got to the sidewalk, and was directly in front of the hotel as the boy he was following strutted through its entrance with an important air. As he came under the full glare of the electric light, Dave caught sight of the tell-tale scar on his cheek.

The fellow did not much resemble the lodging house boy. His hair was neatly cared for, his clothes were of the most expensive kind. For all the world, he suggested a person with plenty of money to spend and wealthy relations.

The boy went up to the desk of the hotel clerk, who bowed and smiled to him as though he was some favored and welcome guest. The clerk handed him a key, and the boy went over to the elevator and stepped in. Dave quickly hastened to the desk.

“Excuse me,” he said, “but I wish to see the young man who just got his key.”

“Yes, room 47. Take the elevator,” vouchsafed the clerk.

“Thank you.”

Dave waited till the elevator had come down. Then he went up to the fourth floor. He went down a corridor, scanning the little porcelain numbers on the doors.

“Here it is,” he said eagerly to himself—“No. 47.”

A light showed through its transom. Tap—tap—tap! Dave knocked smartly on the door panel. Some one, whistling and bustling about within the room, moved to the door, unlocked it, and Dave stood face to face with the boy who had robbed him in the lodging house at Brompton.