ously, then brought it into the house and placed it on the table in her husband's study. It was not an unusual occurrence to have letters left at the door in this manner, as occasionally anonymous letters were left for the detective, giving him hints or advice concerning cases on which he was engaged. To most of these he paid no attention, although sometimes valuable information was brought to his notice in this manner.
This, Mrs. Hardy judged, was another such communication, which was why the person who delivered it had been careful to hurry away after ringing the bell.
Mr. Hardy did not return home until late that afternoon. He had been over to Barmet village where the Federal authorities were closely watching two men thought to be in league with the counterfeiters. Mr. Hardy had followed one man to a near-by city and seen the fellow pass a small package to a woman in black, who had quickly disappeared in a crowd. But the noted detective knew the woman and knew where she could be located when wanted.
The boys had arrived back from school, had left their books at the house, and had set out with Chet Morton for a cruise in the motorboat. When Mr. Hardy came back he glanced over his mail and was settling down to read the evening paper when his wife remembered the
