* * *

First he released the lever, and the door slid shut, entombing Big Tim
within the great cylinder. Then he retraced his way down to the lower
level and through the maze of rooms and corridors. It was not long
before the snow of Titan once more keened against his suit.

He threw his weight against the great door. Only the impulse was
necessary to close it, for the operating mechanism hummed into vibrant
life and it swung shut where it had not been shut before--and locked!
Nor would it open again.

Even if he had wanted to re-enter, that was impossible.

Nellon started back to the ship. With the curious vigor he felt, the
dangers and difficulties of the return trip hardly registered upon him
at all. Gone was his sullen dislike of the ever-raging storm. He plowed
through it with a careless smile, fighting his way over the wild and
tumbled terrain. And it was with no feeling of exhaustion at all that he
finally sighted the great, toothed ice ridge which marked the site of
the camp.

As Nellon shouldered through the narrow cleft which led into the
protected, tiny valley, he remembered to remove the smile of eager
triumph upon his face. It would not go with the story he was to tell.

But it was hardly necessary for him to make the effort. For at the sight
that met his eyes, an involuntary grimace of appalled amazement flashed
over his features.

Where the ship had rested there now was nothing at all, save a smooth
surface of snow. And to his incredulously searching gaze, there was no
indication that anything had ever been here. The little valley was
virgin of any sign of human habitation. Only the bitter wind existed
here, as always it had, keening along glittering ice surfaces, sporting
with the snow.

* * * * *

Nellon felt the sudden nausea and weakness of a terrible fear. But a bit
of flotsam presented itself out of the turbulence of his thoughts, and
he clutched at it with the eagerness of despair.

He must, he told himself, have accidentally encountered a site similar
to the one in which the ship had lain. He had but to find the correct
ridge and everything would be all right.

Nursing this hope, he started on a tour of the vicinity. Soon he
realized, however, that there was no other ridge, and he had to face the
fact that he had originally been at the real site. The only difference
was that the ship was gone.

But Nellon felt that he had to make certain.