Korus Kan had been gazing back with us, but now he turned at my exclamation, shook his head. "Not impossible," he said quickly. "That heat and that light we came through were not generated like the usual heat and light of burning suns--they were generated in empty space by the ether itself!" And as we stared blankly at him he quickly explained himself. "You know that heat and light are but vibrations of the ether of various frequencies, just as are radio-active or chemical rays, and the electro-magnetic waves we use for speech and signaling. Highest of all in frequency are those electro-magnetic waves; next in order of frequency come heat waves; next the red light-vibrations, and down the various colors of light to the lower-frequency violet light vibrations; and below these, lowest of all, the radio-active or chemical rays. Well, our scientists have long known that various of these ether-vibrations have been set up in the ether of outside space by the collision of great ether-currents. By those collisions are formed sometimes electro-magnetic vibrations, interfering with our speech-vibrations as static, or sometimes light-vibrations, glowing without visible source in the heavens and known to us as the zodiacal light. Here in the void, though, where mighty currents of size and speed inconceivable must collide, the vibrations set up were in the frequency-range of heat and of the lower adjoining frequency, that of red light; so that that region we came through is one where the immense ether-currents that we plunged through collide and set up a ceaseless outpouring of heat and light waves there in the ether, in empty space itself." I shook my head. "It seems plausible," I said, "yet the reality of it--that titanic region of awful heat and light----" "It seems strange enough," he admitted, "but it's really no stranger than if it had been a great region of static, or----" A sharp cry from the Spican stabbed through our talk. "The walls!" he shouted. "They're beginning to glow--look----!"