"I begin to think I am not as good a detective as I thought," said Dan to himself. "I am on a false scent, that is sure."
So Dan returned to Union Square.
When he had been asking questions of the cab-drivers he had not been unobserved. John Hartley, who knew Dan by sight, laughed in his sleeve as he noted our hero's inquiries.
"You may be a smart boy, my lad," he said to himself, "but I don't think you'll find the child. I have a great mind to give you a hint."
He approached Dan, and observed, in a friendly way:
"Are you in search of your little sister?"
"Yes, sir," returned Dan, eagerly. "Can you tell me anything about her?"
"I am not sure, but possibly I may. I occupy a room directly opposite the house in which you board."
"Did you see Althea carried away?" asked Dan, eagerly.
"Yes; I was sitting at my window when I saw a hack stop at your door. The door-bell was rung by a man who descended from the hack, and shortly afterward your sister came out, and was put into the carriage."