It must have been something more than a simple desire to satisfy his curiosity, or to gaze up at some window which he might imagine was that of Isa Gernon. Had he been asked, he would have owned to a strange feeling of attraction, drawing him on and on to what proved the most exciting adventure of his life. He knew, though, that he ran great risks, and that, if seen, his visit was sure to be misinterpreted; but another minute had hardly elapsed ere, like his sire in bygone days, he could only yield to the intense desire of affording help where he believed others were in peril. For suddenly, from a corner of the house, where a dense mass of evergreens made more black the shade, came a strange, low, grating noise--a sound that he had never before heard, but which he attributed to the right cause upon the instant; and then, going down upon hands and knees, he tried to govern into regularity his laboured, panting breathing, as he crept cautiously towards the spot from whence the sound had arisen. Book 2, Chapter XXII. "THAT'S IT AT LAST." Brace Norton's heart told him truly: the noise was the grating of a diamond over glass, and it was repeated four times. Then there was a pause, ere at the end of a few minutes came a dull, snapping noise, and one faint tinkle as of falling glass upon the ledge of a window. He stopped, listening attentively, for he seemed by instinct to know what would follow; he almost seemed to pierce the black darkness ahead, and to see an arm passed through a cut-out pane of glass--a fastening thrust back. Yes, there was the dull snap, and now the raising of the sash. No, it could be no sash, for there was a dull creaking as of the rusty hinges of an old iron lattice casement. Then came a soft rustling. Yes, that was the stranger drawing himself up, and passing through the window. Would he fasten it after him? No; it was evidently left open, and all was still. It must be some one who knew the place. What should he do? try and alarm the house? No; he did not fear one man. There was some mystery here; and at the thought of that word mystery, as it seemed to come with a dull impact upon his heart, that heart throbbed and beat still more rapidly, for a strange influence connected mystery with mystery; and Brace Norton, mad almost with excitement, followed to where he had heard the sound, felt in the intense darkness for the window, found it as he had expected--open, and drawing himself up, he leaned in, and listened, half feeling that it was but to receive a fierce blow upon the head; but, no: all was still. "I'll risk all," muttered Brace. "My position as an officer, and my word of honour that I was impelled by good motives, must be sufficient to clear me from all blame."