Darrel hauled the wrecked plates outside the ship to work on them in the open. He could get things done faster out where there was more room to move around. The mysterious girl was still there, quietly watching his every action. He hunched deliberately over the delicate gravitation unit that bulged from the base of one plate. A hyper-thin vibrator rod had been cracked. But he could mend it. He laid down his tools and paused in the work. Lazily, he lighted a Martian cigarette and looked toward the girl. If she were an hallucination, why didn't she go away? Instead, she rose and came toward him briskly--her jet-black hair contrasting vividly with her yellow, short-skirted tunic--walking backward. Darrel scratched his head helplessly and watched as the girl, her back toward him, strode weirdly up to the ship. She turned about and smiled sadly. "Lerrad, retal nruter liw I," she said. "Noos, on I, gniveel ra ooy." "What?" Apparently that gibberish was supposed to mean something. But it didn't. The girl looked a little less woebegone now. "Won trapa la," she said, and looked at the gravity plates spread out on the ground. "That means nothing to me," Darrel said. The Neptunian girl had turned and began to weave her way backward through the plates. It was uncanny the way she did it. She must have eyes in the back of her head! The gait was smooth enough, but it looked so strange in reverse. So damned strange! Darrel followed her with his eyes. His spine was tingling. Like a hawk he watched her. She was a looker. The loveliest creature he had ever seen and ... blazing comets! ... she acted as though she were nutty about him, the way she smiled, jabbered and touched him affectionately. But why the retrogression? Why was she operating like an old film being run off backwards in a projector? Finally, the girl began to walk away again, her face toward him, placing one foot surely behind the other. She smiled cheerfully, waved, and then went on to disappear over the hill. Darrel sat down abruptly. He glued his eyes to the spot where the girl had disappeared. For ten minutes he watched, but nothing stirred on the hill. He noticed now that there were dim shapes thrusting up beyond the hill. They looked like the tops of buildings. A group of them. Probably a city. Why not? The girl had to come from somewhere. But why the devil...! He stared at the gravity plates on the ground. They weren't getting repaired this way. The girl was beginning to get under his skin. The hell with it! He'd work on the plates now. He began to whistle, shrilly and off-key. He always whistled when his lust for adventure was about to be satisfied. Neptune, defiance of the fleet admiral, a dead radio and blown gravity plates ... an impetuous dream-girl ... these added up to adventure. Tomorrow he'd go over the hill and see what was on the other side. * * * * *