After Jack had been at home long enough to find out how things stood, he set himself at work to learn who it was that kept certain people in the neighborhood so well posted in regard to his mother's private affairs. He said not a word to anybody, but worked in secret, for he believed that his efforts would result in the unearthing of a spy who lived in the house. It would add to his mother's troubles if she knew that Jack believed, as she did, that there was some trusted servant who kept an eye on her movements and went to the overseer with a report of them--so he kept his own counsel, and laid siege to Hanson the very first thing. The latter wasn't sharp enough to hold his own with any such fellow as Jack Gray, and Jack learned all he cared to know about Hanson in less than two days. The next step was to find the servant on whom the overseer depended for his information. This looked like a hopeless task, but fortune favored him. One morning he stood in front of the mirror in Marcy's room performing his toilet. The door, which was behind and a little to one side of him, was open, and the lower end of the long hall was plainly reflected upon the polished surface of the looking-glass. So was the slim, agile figure of the small darkey who slipped out of one of the rooms, ran along the hall with the speed of the wind, and disappeared down the back stairs. "That's Julius," said Jack, whose first thought was to call the boy back and make him give an account of himself. "He has been up to some mischief, I'll warrant; but I will see if I can find out what it is before hauling him over the coals." So saying Jack stepped into the hall, and the first door he opened was the one leading into the store-room. There was the open stovepipe hole, and through it voices came up from the room below. He bent a little closer to it, and distinctly heard his mother tell one of the girls to put breakfast on the table and ring the bell for the boys. In an instant the whole secret flashed upon him. He said not a word, but as soon as he returned from the post-office, and Marcy had ridden to the field to carry some instructions to the overseer, Jack went up to his room, leaving orders with one of the girls to send Julius there at once. When he came, the first thing Jack did was to lock the door and put the key in his pocket. "Now, Julius," said he, in his most solemn tones, his face at the same time taking on a fierce frown, "if you are an innocent boy, if you have been strictly honest and truthful ever since I have been at sea, if you have obeyed your mistress and kept your hands off things that do not belong to you----" "Oh, Marse Jack," exclaimed the frightened boy. "Suah hope to die I nevah----" "Don't interrupt me," commanded Jack, with a still more savage frown. "I'll show you in a minute that I have it in my power to find out just what you have done while I have been gone, from the time you stole----"