He frowned at the sight. The main southward migration of unicorns was over but there were often lone stragglers who might appear at any time. He had warned her that someday a unicorn would kill her--but she was reckless by nature and given to restless moods in which she could not stand the confinement of the town. She jerked up her head as he watched, as though at a faint sound, and he saw the first movement within the trees behind her--a unicorn. It lunged forward, its stealth abandoned as she heard it, and she came to her feet in a swift, smooth movement; the spear in her hand and the book spilling to the ground. The unicorn's squeal rang out and she whirled to face it, with two seconds to live. He reached for his bow, knowing his help would come too late. She did the only thing possible that might enable her to survive: she shifted her balance to take advantage of the fact that a human could jump to one side a little more quickly than a four-footed beast in headlong charge. As she did so she brought up the spear for the thrust into the vulnerable area just behind the jawbone. It seemed the needle point of the black horn was no more than an arm's length from her stomach when she jumped aside with the lithe quickness of a prowler, swinging as she jumped and thrusting the spear with all her strength into the unicorn's neck. The thrust was true and the spear went deep. She released it and flung herself backward to dodge the flying hooves. The force of the unicorn's charge took it past her but its legs collapsed under it and it crashed to the ground, sliding a little way before it stopped. It kicked once and lay still. She went to it, to retrieve her spear, and even from the distance there was an air of pride about her as she walked past her bulky victim. Then she saw the book, knocked to one side by the unicorn's hooves. Tatters of its pages were blowing in the wind and she stiffened, her face growing pale. She ran to it to pick it up, the unicorn forgotten. She was trying to smooth the torn leaves when he reached her. It had been one of the old textbooks, printed on real paper, and it was fragile with age. She had been trusted by the librarian to take good care of it. Now, page after page was torn and unreadable.... She looked up at him, shame and misery on her face. "Father," she said. "The book--I----" He saw that the unicorn was a bull considerably larger than the average. Men had in the past killed unicorns with spears but never, before, had a sixteen-year-old girl done so.... He looked back at her, keeping his face emotionless, and asked sternly, "You what?" "I guess--I guess I didn't have any right to take the book out of town. I wish I hadn't...." "You promised to take good care of it," he told her coldly. "Your promise was believed and you were trusted to keep it." "But--but I didn't mean to damage it--I didn't mean to!" She was suddenly very near to tears. "I'm not a--a _bemmon_!"