“Can’t we go along?” asked Joe eagerly.

Mr. Hardy looked at his sons with a smile.

“Well, if you are so anxious to be detectives, I suppose it is about as good a chance as any to watch a crime investigation from the inside. If Mr. Applegate doesn’t object, I suppose you may come along.”

In a few minutes an automobile drew up before the Hardy home. Mr. Applegate was sitting in the rear seat, resting his chin on his cane. When Mr. Hardy mentioned the boys’ request he merely grunted assent, so Joe and Frank clambered into the car with their father. They were tremendously excited at the prospect of being “on the inside” in the mysterious case.