Harris went on. Asteroid Y-3 had only recently been garrisoned and staffed. It had become the primary check-point to halt and examine ships entering the system from outer space. The Garrison made sure that no dangerous bacteria, fungus, or what-not arrived to infect the system. A nice asteroid it was, warm, well-watered, with trees and lakes and lots of sunlight. And the most modern Garrison in the nine planets. He shook his head, coming to the third door. He stopped, raising his hand and knocking. "Who's there?" sounded through the door. "I want to see Corporal Westerburg." The door opened. A bovine youth with horn-rimmed glasses looked out, a book in his hand. "Who are you?" "Doctor Harris." "I'm sorry, sir. Corporal Westerburg is asleep." "Would he mind if I woke him up? I want very much to talk to him." Harris peered inside. He could see a neat room, with a desk, a rug and lamp, and two bunks. On one of the bunks was Westerburg, lying face up, his arms folded across his chest, his eyes tightly closed. "Sir," the bovine youth said, "I'm afraid I can't wake him up for you, much as I'd like to." "You can't? Why not?" "Sir, Corporal Westerburg won't wake up, not after the sun sets. He just won't. He can't be wakened." "Cataleptic? Really?" "But in the morning, as soon as the sun comes up, he leaps out of bed and goes outside. Stays the whole day." "I see," the Doctor said. "Well, thanks anyhow." He went back out into the hall and the door shut after him. "There's more to this than I realized," he murmured. He went on back the way he had come. It was a warm sunny day. The sky was almost free of clouds and a gentle wind moved through the cedars along the bank of the stream. There was a path leading from the hospital building down the slope to the stream. At the stream a small bridge led over to the other side, and a few patients were standing on the bridge, wrapped in their bathrobes, looking aimlessly down at the water. It