Together we scanned the pillar minutely. The faces seemed unbroken, continuous; there was no trace of those thin and shining lines that marked the juncture of the cubes when they had clicked together to form the bridge of the abyss or that had gleamed, crosslike, upon the back of the combined four upon which we had followed Norhala. “It's a sheer impossibility. It's madness to think such a thing, Drake!” I exclaimed, and wondered at my own vehemence of denial. “Maybe,” he shook his head doubtfully. “Maybe--but--well--let's be on our way.” We strode on, following the direction the Metal Folk had gone. Clearly Drake was still doubtful; at each pillar he hesitated, scanning it closely with troubled eyes. But I, having determinedly dismissed the idea, was more interested in the fantastic lights that flooded this columned hall with their buttercup radiance. They were still and unwinking; not disks, I could see now, but globes. Great and small, they floated motionless, their rays extending rigidly and as still as the orb that shed them. Yet rigid as they were there was nothing about either rays or orbs that suggested either hardness or the metallic. They were vaporous, soft as St. Elmo's fire, the witch lights that cling at times to the spars of ships, weird gleaming visitors from the invisible ocean of atmospheric electricity. When they disappeared, as they did frequently, it was instantaneously, completely, with a disconcerting sleight-of-hand finality. I noted, though, that when they did vanish, immediately close to where they had been other orbs swam forth with that same astonishing abruptness; sometimes only one, larger it might be than that which had gone; sometimes a cluster of smaller globes, their frozen, crocused rays impinging. What could they be, I wondered--how fixed, and what the source of their light? Products of electro-magnetic currents and born of the interpenetration of such streams flowing above us? Such a theory might account for their disappearance, and reappearance, shiftings of the flows that changed the light producing points of contact. Wireless lights? If so here was an idea that human science might elaborate if ever we returned to-- “Now which way?” Drake broke in upon my musing. The hall had ended. We stood before a blank wall vanishing into the soft mists hiding the roof of the chamber. “I thought we had been going along the way They went,” I said in amazement. “So did I,” he answered. “We must have circled. They never went through THAT unless--unless--” He hesitated. “Unless what?” I asked sharply. “Unless it opened and let them through,” he said. “Have you forgotten those great ovals--like cat's eyes that opened in the outer walls?” he added quietly.