With Will-o'-the-Wisp now at their head, again were they speeding swiftly onward. Of their guide, Sprigg could at first see nothing, saving his big, dim lantern; but, soon chancing to look a little lower, there, directly under the light, he saw, strange to tell, a pair of red moccasins, gliding on over the tops of the rank swamp weeds, and so lightly that the long, lithe sedge, swaying to the slightest breeze, bent not under their tread. The boy glanced quickly down at his heels to reassure himself that the wispy elf had not stepped into and walked off in his own moccasins. But there they still dangled, just the same, each with a toe at one of his heels. Then flashed it upon his mind that he had not really seen his own moccasins since he had flung them from him up there on the Manitou hill; and so, for aught he or anybody else could tell, red moccasins, if people could only see them, might prove to be as plentiful in the world as Yankee shoes. How long, how far they traveled Sprigg, of course, had no means of judging; but the moon had well nigh climbed to the top of the sky, when, having left the morass far behind them, they came to the foot of another lofty mountain, where, under the shadow of a beetling cliff, yawned the rocky jaws of a huge cavern, into which Will-o'-the-Wisp led the way, his big, dim lamp beginning to brighten the moment it entered the subterranean gloom. Hardly had they crossed the threshold when Sprigg could perceive that they were descending as steeply as, but now, they had been rising. Deeper and deeper into the heart of the mountain they sank; deeper and deeper into the heart of the earth; the ball of light no longer a phosphorescent gleam, but a flame of living fire. But it was not long before they had descended again to the level ground, which they traversed for some distance, then, for the first time since quitting the farther side of the swamp, came they to a pause. Sprigg looked around him. Nothing could he see, saving the bear, the red moccasins behind him, the red moccasins before him; and just over the latter the ball of light, which was now burning with such brilliancy that the luminous hemisphere around it formed a wide and lofty dome in the solid darkness of the cavern. For some moments past he had heard a murmuring sound, as of abundant waters rippling over a rocky bed; and filling all the air was a delectable perfume, as if flowery fields and fruitful groves must be blooming and waving not far off. By this time nothing amazed him. Nothing frightened him. He moved and felt and thought as one in a dream; and so, indeed, had it all appeared to him from the moment he had lost sight of his father, there at the old hunting camp. CHAPTER XIII. Meg of the Hills.