As the Neptunian leader did so, the door of the cell-compartment slid smoothly and silently upward, leaving its opening clear. Without ceremony, then, Marlin and I were motioned to pass inside, and with the four ray-tubes of the guards full upon us we had no choice in the matter. Stepping inside, therefore, we found ourselves in a compartment some ten feet square, whose walls, like all the black walls of the compartment-city, towered for two hundred feet upward around us, the only light the square of dusky sky far above. Then, as Marlin and I stared about us, the door shot smoothly down across the opening, and we heard the soft, shuffling steps of the Neptunian leader and our four guards retreating, outside, leaving us gazing at each other's white faces in silence. Our great mission out to Neptune, our great attempt to save Earth and prevent the wrecking of the solar system, had come to an end at last, with our two friends gone and with Marlin and myself imprisoned here beyond all hope of escape on Neptune's peopled moon! CHAPTER IX Before the Council "Prisoned here on Triton--and Whitely and Randall dead! It's the end, Hunt--for us, and for the Earth!" Marlin's voice was but echoing my own thoughts in that moment, and darkly I nodded. "The end--yes. And less than twelve weeks before that end comes, before the sun's rotatory speed reaches its critical point, before it divides into a double star. We've found the source of the great ray from Neptune, and we're helpless." "Yet the World President--the World Congress----" Marlin seemed to be thinking aloud. "They sent us out to dare all for Earth, and until Earth is destroyed or we are dead we can't give up hope." "But what hope is there?" I asked. "These Neptunians have only reprieved us for the moment from death, for their own purposes. Death will be ours before long, and in the meantime who could escape from this place?" I swept my arm around the cell-compartment, and Marlin considered the place with me as silently and almost as hopelessly as myself. For it was, truly, a prison inescapable into which we had been thrust. The square little compartment's walls were diamond-hard, of that impenetrable black stone-like substance, and they towered two hundred feet above us. There were in them no windows, the only light that reached us being the dusky illumination that came down to us from the compartment's roofless top, far above. That illumination was but small indeed, for the cell-compartment lay in the same twilight band as the great Council Compartment, that band of twilight lying between Triton's dark and sunward sides. By it we could see, however, that the black walls about us were quite vertical and smooth, and that the only break in them was that of the low door-opening, closed now by the smooth, black slab across it.