The sun was setting beyond the little lake as Barney drew the shades over the cabin window again. Dr. McAllen was half inside the built-in closet at the moment, fitting a pair of toggle switches to the concealed return device in there.

"Here we go," he said suddenly.

Three feet from the wall of the room the shadowy suggestion of another wall, and of an open door, became visible.

Barney said dubiously, "We came out of that?"

McAllen looked at him, sad, "The appearance is different on the exit side. But the Tube\'s open now—Here, I\'ll show you."

He went up to the apparition of a door, abruptly seemed to melt into it. Barney held his breath, and followed. Again there was no sensory reaction to passing through the Tube. As his foot came down on something solid in the shadowiness into which he stepped, the living room in Sweetwater Beach sprang into sudden existence about him.

"Seems a little odd from that end, the first time through, doesn\'t it?" McAllen remarked.

Barney let out his breath.

"If I\'d been the one who invented the Tube," he said honestly, "I\'d never have had the nerve to try it."

McAllen grinned. "Tell you the truth, I did need a drink or two the first time. But it\'s dead-safe if you know just what you\'re doing."

Which was not, Barney felt, too reassuring. He looked back. The door through which they had come was the one by which they had left. But beyond it now lay a section of the entrance hall of the Sweetwater Beach house.

"Don\'t let that fool you," said McAllen, following his gaze. "If you tried to go out into ............