"Only significant thing about that," he commented, when he had finished, "is that he starts and finishes within a quarter of a mile of the same place as on the other two nights."
"And that place—" suggested Joe.
"Is near old J. Anson's driveway."
"Looks mighty suspicious to me," said Joe.
"Does to me, too; but, as I have said before, you can't raid a man's private castle on any such flimsy proof as that. You've got to have the goods.
"Tell you what," he said after a moment's silence, "sometimes our natural ears and eyes are better than all these instruments and wires. I'm going out there to-morrow night alone and on foot."
"Might work," said Joe thoughtfully, "but whatever you do, you must be careful."
"Careful?" said Curlie scornfully. "There are times when a fellow can't afford to be careful. This thing's getting serious." He glanced over a second message from the head office of his bureau. It was couched in no gentle terms. He was told that this intruder must be caught and that at once if he, Curlie Carson, wished to hold his position as chief of the secret tower room station.