When Ken opened his eyes next morning and looked out he saw that the house was wrapped in fog. There had been no rain at all since the day a week ago when the wind had torn the "sprinkling system" to pieces and blown all the tattered clouds away. That was the day he had found Flicka, and it terribly hot since then. They had hardly been able to stand the sun out on the terrace. They had gone swimming in the pool everyday. On the hills the grass was turning to a soft tan. Now there were clouds and they had closed down. After a severe hot spell there often came a heavy fog, or hail, or even snow. Standing at the window, Ken could hardly see the pines on the Hill opposite. He wondered if his father would go after the yearlings in such a fog as this-they wouldn't be able to see them; but at breakfast McLaughlin said there would be no change of plans.It was just a big cloud that had settled down over the ranch-it would lift and fall-perhaps up on Saddle Back it would be clear. They mounted and rode out. The fog lay in the folds of the hillls.Here and there a bare summit was in sunshine, then a little farther on came a smother of cottony white that soaked the four riders to the skin and hung rows of moonstones on the whiskers of the horses. It was hard to keep track of each other. Suddenly Ken was lost-the others had vanished. He reined Shorty and sat listening. The clouds and mist rolled around him. He felt as if he were alone in the world. A bluebird, color of the deep blue wild delphinium that dots the plains, became interested in him, and perched on a bush nearby; and as he started Shorty forward again, the bluebird followed along, hopping from bush to bush. THe boy rode slowly, no tknowing in which direction to go. Then, hearing shouts, he touched heels to Shorty and cantered and suddenly came out of the fog and saw his father, Tim, and Ross. "There they are!" said McLaughlin, pointing down over the curve of the hill. They rode forward, and Ken could see the yearlings standing bunched at the bottom, looking up, wondering who was coming. Then a huge coil of fog swirled over them and they were lost to sight again. McLaughlin told them to circle around, spread out fanwise on the far side of the colts, and then gently bear down on them so they would start toward the ranch. If the colts once got running in this fog,he said,there'd be no chanve of catching them. The plan worked well; the yearlings were not so frisky as usual and allowed themselves to be driven in the right direction. It was only when they were on the County Road, and near the gate where Howard was watching, that Ken, whose eyes had been scanning the bunch, as they appear and disappeared in the fog, realized Flicka was missing.