In the wild mountain district where Corporal Dexter and a few knightly comrades rode in the service of the King's Law, there was not more than one officer available to patrol each two hundred square miles of territory. In the back hills were certain inaccessible regions never visited by civilized beings. A crime committed in such an out-of-the-way valley as this might remain unsuspected for years. The murderer of Constable Graves could have no inkling that a second officer had just ridden down through the passes. It probably did not occur to him that there was any danger of pursuit, and he did not try to mask his trail. The tracks led for a distance through the thick timber, and then slanted down to the brook and continued northward along the unobstructed course of the stream. The killer walked with a free, unhurried stride, without pausing anywhere by the way to listen or glance behind. Particles of feathery snow still held loosely around the edges of the prints, and Corporal Dexter knew that the maker of the tracks was traveling not more than twenty minutes ahead of him. For a distance of two miles or so the trail followed the meanderings of the winter-bound brook. But at last, near the banks of a forking stream, the hob nails turned aside and entered a dismal spruce forest that extended upward over the valley slope in an unbroken area of overweighted tree tops. The failing twilight scarcely filtered through the interlaced branches overhead, and Dexter found himself groping among the shadowy tree shapes in a purple-tinged dusk that thickened and deepened as he advanced. He quickened his pace, hoping to run down his quarry before night overtook him. But he had traveled scarcely five hundred yards among the spruces, when he discovered open ground ahead, and stopped short at the edge of a stumpy clearing, cut in the midst of the standing timber. Before him in the darkness, vague and unreal as the apparition of a wood troll's dwelling, there loomed the dingy outline of a low-roofed log cabin. The horseman instinctively reached behind to grab his pony's muzzle. But the precaution was needless. Susy stood with drooping head, and apparently lacked interest to announce her arrival. Dexter eyed her sharply, with a passing glance at the burden she carried, and then turned back to reconnoiter the shadows. He had not heard of any settlers living on this side of the range. Apparently the builder of this cabin was a newcomer. The logs showed recent