The girl sat silent, her eyes fixed upon the rushes slowly waving in the stream. A motor-launch passed them, making a high wash against the bank, but she took no heed. She was still thinking of that strange occupant of the house in Bridge Place. Three times during the past week she had, indeed, visited her aunt in an endeavour to discover something more. Boyne had been out, as usual, therefore she had been able to examine the place thoroughly. She had ascended to that locked room on each occasion, and had listened there. Once in the silence she had heard a distinct movement, a slight rustling, within. Yet afterwards, as she had reflected, she wondered whether it had not been due to her imagination, or perhaps to a blind flapping at an open window. When one is suspicious, it is so easy to imagine queer circumstances. "I only wish we could solve the mystery," she remarked wistfully. "It worries me. Auntie seems quite unconcerned." "Because she has no suspicion, worthy old soul. She has no knowledge of Mr. Boyne’s nocturnal visits with food to his friend." "Why shouldn’t we tell her, and then she’ll be on the alert?" suggested the girl. "She might discover something." "She might—but more probably she would be too eager, and thus put Boyne upon his guard," remarked the young fellow. "No. We must work together in strict secrecy if we intend to be successful." "But who can he possibly be hiding?" The young man in flannels shrugged his shoulders, and replied: "I confess that the problem is getting on my nerves. The more I think it over the more inscrutable it becomes. Mischief is being worked somewhere. Of that I feel confident. All the actions of our friend Boyne point to it." "But that shroud? Why does he wear it?" asked Marigold blankly. "As a disguise, without a doubt. Perhaps the person upstairs has been confined there so long that his mind has already become deranged, as is inevitable after a long period of solitary incarceration, and Boyne now takes the precaution of adopting the simple disguise so that his friend should fail to identify him. He may have done his captive some great injury—or something." "True; but, if he has, it was not in order to gain. Bernard Boyne is a comparatively poor man. My aunt says that he seems to have only just sufficient money to make both ends meet." Gerald Durrant drew a long breath. Upon his countenance was an expression of doubt.