"Ye-e-s," agreed Mavis doubtfully. "It seems to have gone rather smaller, though. I don't remember that clump of ferns at the bottom." "Well, there's the first cross at any rate. Come along." But when they reached what they supposed to be the first cross they were more doubtful still. It was quite unfamiliar. Moreover, there was no road within sight of it. "We--we've come wrong!" faltered Merle. "There must be several of these crosses." "Let's go back to that one over there, then perhaps we shall find our first one." But meanwhile the treacherous mist was rolling up thicker and thicker. The girls hurried back as fast as they could, but this time they missed the cross altogether. There is nothing so easy as to get lost in a fog on the moors. Thoroughly frightened, they called to Uncle David, but they could hear nothing in reply. They wandered on, hoping he would sound the hooter and so give them some clue to his whereabouts, but everything was deadly still. It seemed as if a great white wall had arisen and shut them up in some elfin castle on the moor. "We're pixie-led. That's just all about it," said Merle. "I told you it was an unlucky day." "Well, look here, we mustn't go too far! If we walk on like this we may be going straight away from the road, and might tramp miles or get into a bog. We'd better stay where we are and shout every now and then, and perhaps Uncle David will find us." Two very forlorn girls, feeling extremely chilly and cold in the clammy fog, squatted down on the heather and took it in turns to call "Coo-e-ee!" "What are we to do if we have to stop here all night?" asked Merle, nearly crying. "I don't know!" "How long do these mists last?" "Oh, days and days sometimes I suppose!" "Should we be dead before morning?" "Oh, I hope not! Shout again!" They both called together, but there was no response. "I'm going to count a hundred, and if we hear nothing by then I shall walk on somewhere. It's so bitterly cold sitting still," said Mavis, who was shivering. She counted aloud, and at the end they gave a frantic shout. Not even a bird rustled in reply. "Well here goes, there's nothing for it but a plunge," said Mavis. "I've not the glimmer of an idea which way to take." "I shall follow my nose," said Merle, setting off. "Don't go too fast or you'll lose me. Let me take hold of your arm. We never came this way, I'm sure. We certainly didn't pass a little stream." "Any way is better than no way," said Merle desperately. "Hello! why there's the road!" The relief at finding themselves back upon the track of civilization was intense. They ran joyfully along, and in a few moments came upon Uncle David, just screwing on his last nuts and whistling to himself quite unconcernedly. "Where have you two been?" he asked.