Most singular of all was the light that each of these musicians carried. This light came from neither torch nor lantern, but radiated in sparks and flashes from oval disks worn, jewel-wise, on the breast. By what fuel these incandescent fires were fed was not apparent. They burned with a clear white brilliance, illuminating each flowing figure with startling vividness, and filling the beholder, ignorant of their nature, with wonder at their admirable adaptability to the needs of a subterranean world. To Leighton these strange lights were much more mystifying than all the rest of the apparition--for as yet it was difficult to regard the approaching throng as being anything more real than an apparition that one expects to have vanish away almost as soon as it makes its appearance. But these musicians, weird and unearthly though they first seemed when seen at a distance, as they drew nearer, proved to be substantial, flesh-and-blood human beings right enough. Their dark skins and aquiline features gave evidence, for one thing, that they were of Indian origin and not inhabitants of the remote, invisible fairyland that they appeared to the fervid imaginations of some of Leighton's companions. Doubtless, argued the savant, they were a band of revelers--or bandits--from the city to whom the secrets of the cave were familiar. But where they had picked up such extraordinary means for the illumination of their merry-making was more than he could fathom. Lights? They were unlike any lights he had ever heard of. All that he could make of it was that these illuminated disks belonged to the marvels of a hitherto unknown world of science, marvels among which he counted the Black Magnet and--possibly--that disappearing wall at the entrance to the cave. As these people showed no sign of hostility, the explorers began to hope that through them they would win their way out of the cave. Certainly, they were worth cultivating with this end in view. Hence, Miranda and Herran looked stealthily at their revolvers and restored them as quickly as possible to their hip-pockets, while such a burst of confidence seized Mrs. Quayle that she prepared and was actually seen to exhibit one of her most ingratiating smiles for the benefit of the approaching Indians, at the same time expressing in a loud voice to Una her approval of their music.