On another night, two coyotes approached the cave. Treve stood his ground in the narrow passageway, resisting their lures to venture forth; that they might take him from opposite sides. One of them, feinting a dash, in hope of drawing him out, ventured too close. The next moment he went howling back to his mate; a broken forepaw dragging limp. The two marauders contented themselves with lurking out of reach for the rest of the night. In the dawning they set off in search of easier prey. Nor did they return. Luckily for Treve, the wolves and the bulk of the other large beasts of prey had not yet crossed the rivers or come down over the ledge, for the winter. As it was, his labors were wearing enough; in leading his hungry flock to stretches of snow not too deep or too hard for them to dig through in search of grass. Then dawned a morning when the temperature was many degrees below zero. It was the third morning of the first real ice-grip weather of the young winter. Another night or so of such awful cold would bring the hungry wolf-packs down from their higher hunting grounds;--down to where the scent of sheep would muster them to the slaughter. On that morning the hollow, below the spring-trickle, was frozen solid. Perforce, Treve led his sheep afield in search of water. He led them to the Chiquita River, a quarter mile below the ledge. As they neared it, he left them and bounded forward. To his amazed near-sighted eyes, there was a wide and solid bridge spanning the stream at this narrow point;--a bridge which, assuredly, had not been there when last he visited the river. It shone like white flame in the bitter cold sunrise. The freshet had long since subsided. The freezing of the pools near the summit, for two nights, had made the stream sink still lower. Here, the queer trend of the water into a cataract, and the sudden visitation of the supreme cold had caused a phenomenon familiar to every one who has seen northern waterfalls in winter. An ice-bridge had formed over the shallow cataract. Now, Treve had no method of knowing whether this seemingly firm bridge was strong enough to hold an army or too fragile to support a mouse. Nor did he stop to test it. Enough for him to realize that he and his sheep were no longer cut off from the world. Wheeling, he bunched his flock, with clamorous barks and with flying feet; and fairly hurled them at the bridge. Laggards and cowards were nipped or hustled. Fearing their guard more than they feared the uncertain ice, the forty-seven wethers rushed the bridge; slipping and slithering across it, helter-skelter, singly and in twos and threes. Over they surged, in safety; the big young dog driving them fast and mercilessly. Early winter dusk had fallen. Royce and Fenno were entering the ranch house at the close of their day’s chilly work, when a shout from Toni, at the barns, made them stop and turn around.