Enough of the details remained to shock him into an awareness of his desperate plight. The rejuvenation process had worked too well, for Donovan had waited dangerously long. As the body grew younger the tissue cells were consumed and youthful cells replaced them. The process that had worked for body cells did the same for the cells of the brain. Those portions of the brain containing the knowledge and ability of a 70-year-old man were gradually being replaced with new, untrained cells. He had failed to re-educate himself as new cells replaced the old, and had come to the brink of disaster. Sufficient intelligence and manual dexterity remained to compensate for that, but in a few years the task would be hopeless. * * * * * Excitedly, for he knew his life depended on it, he rummaged through his book shelves looking for a copy of his first story, "Turn Backward, O Time!" It contained, he remembered, a concise, accurate description of the mechanism for the time-machine. The magazine itself was old, the sheets turning brown and the pages breaking. He read the story in haste, vaguely remembering the plot. The actual description of the operating mechanism, he found to his consternation, was missing. "I will cut one or two paragraphs," the editor had said, "_They are not convincing, technically ... they lack verisimilitude!_" Not convincing! If he did not find them he was doomed to become a child, and then a babbling idiot of a baby and would disappear entirely within twenty years. He telephoned the magazine's office and asked for the editor. "Sorrree," the secretary said, "Mr. O'Sloane is quite ill. The doctors are afraid he might not pass through the night. He's very old, you know." "Can he speak?" Donovan asked desperately. "He's had a stroke. Can't say a word. Completely paralyzed, Sorrreee." Donovan cursed the carelessness that had led him to this difficult position. He knew that O'Sloane kept the originals of his favorite stories in a collection in his office. If O'Sloane died it was possible that some enterprising youthful editor would destroy the old manuscripts in a fit of house-cleaning. "This is Donovan," he said quickly, "I am trying to locate the original copy of "Turn Backward, O Time" which O'Sloane has in his files. I must study the original papers; it's extremely important. If there is a substitute editor, will you ask him to keep an eye open for it." "Cerrrtainleee." He sighed and took a taxi to the editorial office. It would be best to get it as quickly as possible. The original manuscript was quite safe. Donovan need only copy the original description. Even if he were no longer able to grasp the theory of it, the machine was still easy enough to build from the description.