Swiftly as before that great change was accomplished, and then, as there began again the dull clamor of activity upon the sunward side, Marlin and I turned from our listening attention. But at that moment we heard a staccato rattle of speech outside our door, and an instant later the great black slab of that door slid sharply upward and three Neptunians moved inside the cell. The foremost one of these bore on the metal armor of his great green disk-body a crimson circle that marked him as one of the Neptunian officials. The other two were apparently guards brought in as a precautionary measure, their force-ray tubes unsheathed and leveled unhesitatingly upon us. The Neptunian official carried in his grasp a small octagonal object or mechanism with a simple button-control, which we gazed at curiously. He touched the button-control of it, and there sounded from it a series of swift, sharp snaps of sound exactly like those of the Neptunians' staccato speech. Then, speaking aloud himself, he motioned from himself to us, and then to the mechanism. It was Marlin who first understood his purpose. "The Neptunian language!" he exclaimed. "This one has come to teach it to us, to make it possible for them to communicate with us." "But the mechanism?" I said. "What is its purpose?" * * * * * Marlin stared at it a moment, then reached forth and touched its round button-control, bringing from the mechanism an irregular succession of snaps of sound. "It's for us!" he said suddenly. "They know that with our different bodies we can't make the sharp, snapping sounds that are their speech, so have brought this mechanism to us to serve us as an artificial voice!" The Neptunian official, as though he had understood us, motioned again to the mechanism and then from himself to us, at the same time uttering a few speech-sounds as though in explanation. It was plain, indeed, that his object was to teach us the strange Neptunian speech. Pointing to himself, and to the two guards, he uttered a succession of five sound-snaps, irregularly spaced, over and over again, until it was evident that they represented the name of the Neptunian races. Then Marlin and I attempted with the little speaking mechanism to reproduce those five snaps of sound, and after experimenting for a time with the mechanism's button-control we succeeded. That done, the Neptunian pointed to us and uttered another short succession of sounds, another word, which we then learned to utter on the mechanism also.