The trail now led over solid granite and could be followed only by little cairns or heaps of stone, placed at some distance apart, but in the clear air easily seen from one to the other. She moved rapidly, for the way was no longer steep, and ere long the tripod which marked the highest point, and near which Robin had seen the strange waxen flower, was outlined against the sky. A moment later when she looked it seemed to her less clear. The air, too, had a chill damp feeling. She turned quickly to look behind her, and uttered a little cry of surprise that was almost terror. The cloud ghost was upon her--she was already enveloped in its trailing cerements. Behind, all was white, and when she turned again the tripod too had well-nigh disappeared. As if about to lose the object of her quest, she started to run, and when an instant later the beacon was lost in a thick fold of white she again opened her lips in a wild despairing cry. Yet she did not stop, but raced on, forgetting even the little guiding cairns which pointed the way. It would have made no difference had she remembered them, for the cloud became so dense that she could not have seen one from the other. How close it shut her in, this wall of white, as impalpable and as opaque as the smoke of burning grass! It seemed a long way to the tripod. It must have been farther than she had thought. Suddenly she realized that the granite no longer rose a little before her, but seemed to drop away. She had missed the tripod, then, and was descending on the other side. Turning, she retraced her steps, more slowly now, trying to keep the upward slope before her. But soon she realized that in this thick and mystifying whiteness she could not be certain of the level--that by thinking so she could make the granite seem to slope a little up or down, and in the same manner, now, she could set the tripod in any direction from her at will. Confused, half terrified at the thought, she stood perfectly still, trying to think. The tripod, she knew, could not be more than a few yards distant, but surrounded by these enchanted walls which ever receded, yet always closed about her she must only wander helplessly and find it by mere chance. And suppose she found it, and suppose she secured the object of her search, how, in this blind spot, would she find her way back to the trail? She recalled now what Robin had said of keeping the trail in the fog. Her heart became cold--numb. The chill mist had crept into her very veins. She was lost--lost as men have been lost in the snow--to die almost within their own door-yards. If this dread cloud would only pass, all would be well, but she remembered, too, hopelessly enough, that she had told no one of her venture, that no one would know where to seek her.