Having passed through the great portal that separated them from Anitoo and his men, they were soon following a narrow path that ran between two high walls of rock. This path was at first scarcely discernible. As they turned a sharp corner, however, the darkness gradually lifted and they found it possible, for the first time, to distinguish certain objects a considerable distance ahead of them--and judging by the direction in which the shadows from these objects were thrown, it was evident that the light was not a reflection cast by torches carried by warring cavemen. This discovery was hailed as a momentous one, open to two interpretations. Since, as every one knows, caves are never lighted from sources contained in themselves, they must now be nearing another party of cavemen, who were carrying lanterns, or else, through some twist in subterranean topography, they had stumbled upon an unexpected passageway to the outer world. No sooner was the latter possibility suggested, however, than its improbability was recognized. No rays from sun or moon were ever like these--blue, flickering, ghostly--illuminating the grotesque forms around them. This light had a tingling quality, as of sparks that snap and glitter when they are thrown off from an electric battery. It was certainly not sunlight, or moonlight either, as the explorers quickly realized. There remained the idea that it came from lights carried by an approaching band of cavemen. "It is like the torches of Anitoo's musicians!" exclaimed Una; "it's not from the sun." "It begins to be too bright, and at the same time too far off, for that," objected Leighton. "It is one big fire----" said Miranda. "A bonfire," interjected Andrew. "----and when we come there we will see." Pressing on along this path, the light steadily increased, although revealing to the explorers nothing of its origin. They could walk now at a fairly round pace, and as their range of vision extended their attention was completely taken up in a study of the strange objects to be seen in the unknown world about them.