Engrossed, he moved an inch forward, craned his head, and in that moment it happened. Beneath his weight a section of earth and rock crumbled, cracked, slid forward, and he plunged headlong to the floor below, striking his skull with stunning force! He came to himself, staring up into the dour-looking face of a tall man. He recollected pitching forward among the birds and the machines. But the birds and the machines had disappeared and he was lying in an odd room without windows but lit with a soft radiance. Bewildered, he sat up. "Who are you?" he demanded. The man's beard looked straggly, untrimmed. "My name," he said, "is Reubens--Professor Reubens." Professor Reubens! Talbot gasped. "Not the scientist who disappeared?" "Yes--as you've disappeared." "What!" "Through the machine." It was a moment before Talbot understood. "You mean...." "That you are a prisoner in a sub-atomic world." Talbot now realized with startling clearness what had happened to him. When he had fallen into the crypt the weird birds had directly placed him in the cabinet and transported him to their own world. In other words, he and Reubens and everything he saw about him were infinitely small creatures in an atom-world. He and the Professor were trapped! And when Manuel blew up the only means of return.... "How long have I been here?" Talbot asked hoarsely. "Five minutes at the most." Then, at the shortest, the way to earth would exist twenty minutes longer. Twenty minutes.... Incoherently he told Reubens of what had happened in Arizona since his disappearance, of his own misadventure. "Aye," said the Professor, "I knew as much. Nor do these inhuman birds intend stopping with the use of seed globes. More devilish weapons than that they plan using against earth. Oh, they are fiends, fiends! Already have they wiped out civilization and intelligent life on other planets in this sub-atomic system and introduced their own." He stopped, shuddering. "Nor is it to be wondered at that no birds were seen after the first attack on Oracle," he went on. "They do not fight in person, as do we ourselves, but through proxy, directing machines from centers of control. In powers of destruction, they are immeasurably ahead of man. Thank God you discovered their headquarters in the deserted mine and have spread the gas for its destruction. But the rage of the birds at such a defeat will be terrible. They will undoubtedly torture me in an effort to make me reveal the basis of my invention so that they can resume the attack on earth. So we must escape." "But how--where?" "I have thought that out. It is one chance in a thousand. Undoubtedly we will be killed. But that is better than being tortured or living in this world. Look." He held up a pearl-handled pen-knife. "The birds are smart, all right, but they don't quite understand clothes, wearing none themselves. They found your revolver, but overlooked this." "Of what good is it?" "To cut our way out of this cell."