wheelchair rolled slowly toward a blank wall, and an invisible door snicked open just before it arrived.

“Come along,” quavered The Visitor. “Step lively.”

Garth leaped forward and just managed to pull his tail through the doorway as the door slid shut again.

Garth dropped his jaw in amazement. He stood in a long corridor that seemed to stretch to infinity in both directions. The light was bright, the walls featureless. The floor was smooth and unmarred. While Garth glanced unhappily behind himself to notice that there was no sign of the doorway through which he had entered, The Visitor’s wheelchair buzzed swiftly into the distance toward the left.

Garth was startled into action by a high-pitched voice beside him that said, “Well, get a move on! Do you think I want to wait for you all day?”

While Garth hustled toward the wheelchair, he noticed that The Visitor had stopped and was apparently chuckling to himself. He was hunched over, his shoulders were shaking, and his toothless mouth was split in what might have been intended for a grin.

“Fooled you that time, youngster,” he laughed as Garth drew up beside him. “Got speakers all over this ship. Now just duck through this door here and tell me what you think of what you see.”

A small door slid open and Garth followed the wheelchair through. At first he thought he had stepped through a teleportation system. He appeared to be out of doors, but not on Wrom. A cool breeze blew on his face from the ocean, which stretched mistily to a far horizon. He was standing on a sandy beach and waves rolled up to within a few yards of his feet. The beach appeared to be about five hundred yards long, carved out of a rocky seacoast; great rocks jutting into the ocean terminated it to left and right.

“Well, boy?” asked The Visitor.

“It’s amazing. Your voice even has that flat tone voices get in the open. I suppose it’s some sort of three-dimensional projection of a scene back on Earth? It sure looks real. I wonder how big this room really is and how far away the screen is.” Garth stuck out his hand and walked down toward the water. A large wave caught him, tripped him and rolled him out to sea.

Sculling with his tail, he soon swam back to shallow water and climbed back to the dry sand, puffing and coughing.

“You might have drowned me!” Garth shouted disrespectfully. “Are you trying to kill me?”

The Visitor waved weakly until he recovered his breath. “That was funnier than anything I’ve seen in years,” he wheezed, “watching you groping for a screen. That screen is a quarter of a mile away, and it’s all real water in between. It’s our reservoir and our basic fuel supply and a public beach for entertainment, all rolled into one.”

“But I might have drowned! No one on Wrom except a few small fish knows how to swim,” protested Garth.

“No danger. Your ancestors came out of the water relatively recently, even if the seas are gone now. You’ve got a well-developed swimming reflex along with a flat tail and webbed feet and hands. Besides, I told you not to touch anything. You stick close to me and you won’t get into trouble.”

“Yes, sir. I’ll remember.”

“There used to be hundreds of people on that beach, and now look at it.”

“I don’t see anything alive.”

“There are still plenty of fish. Most of them did all right, even through the crash. Come along now. There’s more to see.”

A hidden door popped open and Garth stepped back into the corridor. He trotted beside The Visitor for several minutes, and then another door popped open. It led to a ramp. Garth climbed it to find himself again in wonderland. He was