He looked up to see how much nearer the mountain tops had come. To his disappointment he could not see them at all： only a vague greyness， rolling down towards them. He had never been in mountain country before and was surprised. “It‘s a cloud，” he said to himself， “a cloud coming down. I see. Up here in the hills one is really in the sky. I shall see what the inside of a cloud is like. What fun！ I’ve often wondered.” Far away on his left and a little behind him， the sun was getting ready to set.
They had come to a rough kind of road by now and were making very good speed. But Shasta‘s horse was still the last of the lot. Once or twice when the road made a bend （there was now continuous forest on each side of it） he lost sight of the others for a second or two.
Then they plunged into the fog， or else the fog rolled over them. The world became grey. Shasta had not realized how cold and wet the inside of a cloud would be； nor how dark. The grey turned to black with alarming speed.