Then, outside, there was a sudden louder shrieking roar. A flood of red light poured through the columns, and there was a terrific crash upon the dome. Dense clouds of hot purple vapor poured into the vast room. One of the flying lights had landed upon the roof. The charging throng behind us stopped and ran about in confusion. We darted out through the purple clouds and ran for the shadow of the nearest building. We kept close by the mighty walls until we reached the gate. Daring the terrors of the night, we ran out and down the narrow trail. By dawn we were several miles from Astran in the direction of the shining lake. CHAPTER VII The Silver Lake At the coming of day we were walking over a gently rolling scarlet plain, scattered with gigantic solitary boulders, that sloped gradually down to the Silver Lake. The lake lay flat and argent white, clad in all the ominous mystery of that strange world, calling, beckoning us on, challenging us to learn the secret of the fartherest bank of purple fog, with a grim warning of the doom that might await us. The red fern-like sprays waved gently in the breeze, and the vivid, tiny white flowers seemed to sparkle with a million glancing rays, like frost in the sunshine; but the deep intensity of the red color lent a weird and unpleasant suggestion of blood. Beyond the Silver Lake, low hills rose, faint and mysterious in the purple haze. Melvar walked beside me when the way was smooth enough; she was talking vivaciously. She had a keen sense of humor and a lively wit. She seemed to have an almost childishly perfect faith in my power and that of my guns--but I was far from feeling confident. At sunrise we stopped by a little pool of clear water, drank, and made a meal of the abundant yellow fruit. Astran, with the scintillating fires kindled again in its jeweled towers by the rising sun, lay far behind and above us. When we had finished eating, Melvar stood looking for a long moment at its glorious sparkling light. She murmured a few words beneath her breath, in the Astranian tongue, and turned again toward the Silver Lake. In two hours we came to the shore of the great lake. The red scrub grew up to the brink of a bluff a dozen feet high. Below was a broad, bare sandy beach, with the gleaming waves, quicksilver white, rolling on it two hundred yards away. For a few minutes we stood at the edge of the cliff, in the fringe of crimson brush, and let our eyes wander over the vast flat desert of flowing argent fire. We peered at the misty red hills beyond, trying to penetrate their mysteries, and to read what lay behind them. Then we scrambled down on the hard white sand. Naro grasped his weapon and looked up and down the beach. "It is along the shore of the Silver Lake," Melvar said, "that the Purple Ones are most frequently found."