The detectives did not notice that they were being followed by a youth, and it is doubtful if they would have paid any attention to him if they had.
The foot of the first detective was on the lower step of the stairway leading to the door of the suspected house when suddenly a shrill whistle cut the air from the direction of the corner, and Ted turned to see the policeman strike the man in the check suit a blow with his club.
"Curse him, he's tipped us off," said the detective. "Come on, we've got to rush them now."
Quickly the three sprang up the steps, threw the door open, and entered a long hall.
"Back room," said one.
Ted was following them as closely as he could without being noticed and warned away.
He saw a big, fine-looking policeman entering by a back door.
"That's it," said one of the detectives, motioning to a door.
The policeman walked boldly to the door and threw it open.
As he did so a shot rang out, and the policeman staggered back and fell, a crimson stain covering his face.