They found themselves in a second corridor, one more narrow than that in which they had been imprisoned. The same grey light glowed from the walls. But as Dane stepped forward his feet were cushioned and he looked down to see that his boots stirred fine dust, dust thick enough to coat the floor an inch or more in depth.
Mura freed his belt torch and sent its beam ahead. Save where they had disturbed it, that dust was smooth, without track. No one had walked this way for a long, long time-perhaps not since the Forerunners had left this mountain citadel.
“Hey!” Kosti’s startled cry drew their attention. Where the narrow door had been was now once more smooth wall. Their retreat had been cut off.
”They’ve trapped us again!” he added hoarsely. But Mura shook his head.
“I think not. There is perhaps some closing mechanism that operates automatically, which we activated merely by passing it. No one uses this passage-or hasn’t for years. I am willing to believe that Rich and the others do not even know of its existence. Let us see where it will lead us.” He pattered ahead eagerly.
The corridor paralleled for a space that wider hall which had been turned into a trap. Its smooth walls showed no other hint of openings. There might be innumerable doors along it, all attuned to some combination of whistled notes, Dane thought, but they had neither the time nor the energy to explore that possibility.
“Air-”
Dane did not need that exclamation from Mura-he had already scented it. Cutting across the dusty, dead atmosphere of the way was a breath of stronger air-a puff which carried with it the chill of the outer world, and a very faint hint of growing stuff which out in the open might not have been discernible at all.
The three reached the point from which that came, and found an opening in the wall. Beyond, audible above the beat of the installation, was a rushing sound. Dane thrust his hand out into the square of dark and the current of air, blowing as if sucked in by the mountain, pulled gently at his fingers.
“Ventilation system,” Kosti’s engineering knowledge was intrigued. He put head and shoulders into the opening. “Big enough to travel through,” he reported after using his torch up and down the channel beyond.
“Something to keep in mind,” Mura agreed. “But first let us get to the end of this particular way.”
In twenty minutes they got to the end, another blank wall. Kosti was not disheartened this time.
“Bring out the tootler, Frank,” was his solution, “and open her up for us-”
But Mura did not reach for the pipe. Instead he swept his torch carefully over the wall. This was not the smooth material of the Forerunners’ work, but the rough native stone of the mountain.
“I do not think that this will respond to any tootling,” he remarked. “This is the end of the road and it is truly sealed-”
“But a passage should lead somewhere!” Dane protested.
“Yes. Undoubtedly there are many openings we cannot see. And we do not know the sonic combinations to unlock them. I do not think it wise to waste tune trying to find any such. Let us return to that air duct. If it supplies a series of passages it may let us out into another one-”
So they went back to the duct. As Kosti had said, it was large, large enough that the jetman and Dane might travel it-if they went on hands and knees. And it lacked the dust which carpeted the side passage.
One after another they swung into it, and into the dark as they moved from the entrance. For here was none of the ghostly radiance which gave limited light to the corridors.
Mura crawled first, his torch beaming on. They were in a tube of generous proportions and around them passed air which had come from the outside. But the steady beat of the installation crept up their arms and legs from contact with the surface.
The steward switched off his torch. “Light ahead-” his voice was no more than a husky whisper.
When Dane’s eyes adjusted to the lack of torchlight he saw it too-a round circle of pale grey. They had found the end of the vent.
But as they came up to that exit they found themselves fronted by a grille of metal, a mesh wide enough to allow passage of their hands through the squares. And beyond it lay a vast open space. Mura looked through and for the first time since he had known him Dane heard the unusually calm steward give a gasp of real surprise. Dane prodded his back suggesting that he and Kosti also wanted to see.
Mura flattened himself against the wall of the tube so that Dane could take his place. The space beyond was huge-as if the whole of a mountain interior had been hollowed out to hold a most curious structure. For, when the cargo-apprentice squirmed forward he looked down upon the strangest building he had ever seen.
It was roofless, its outer walls coming up to within six feet of the ventilation grill. But those walls-they ran crazily at curves and angles, marking off irregular spaces which bore small resemblances to ordinary rooms. Corridors began nowhere and ended in six- or eight-sided chambers without other exit. Or a whole series of rooms were linked-for no purpose since the end ones possessed neither entrance nor exit.
The walls were thick, at least three feet wide. A man could swing down and walk along them, so discovering the purpose of the muddled maze, or winning completely across the cave. And since there was no way back for them, that is what the Terrans must do. Dane inched back to allow Kosti his turn at the grille.
With a grunt of surprise the jetman viewed the weird scene. “What’s it for?” he wanted to know. “It doesn’t make sense-”
“Maybe not our brand of sense, no,” Mura agreed. “But the solidity of the work suggests a very definite purpose. No one builds such erections for a mere whim.”
Dane reached over Kosti’s shoulder to pull at the grille. “We’ll have to get through this-”
“Yes, and then what?” the jetman wanted to know. “Do we grow wings?”
“We can get down to the top of that wall. They’re wide enough to walk on. So we can get across on them-”
Kosti was very quiet. Then his big hands went out to the grille, testing the fastenings. “Take a while to get this loose.” From his belt he took his small tool kit and busied himself about the frame of the netting.
They ate while they crouched there, rations from their emergency kits. Since the grey light of the cave neither waxed nor waned, there was no measurement of time save as recorded on their watches. It might have been the middle of the night-their time keepers said it was afternoon.
Kosti gulped his vita-cube and went back to work on the grille. It was well into the second hour before he put away his tools.
“Now!” he pushed gently at the grille and it folded out, leaving the end of the tube open. But he did not swing through as Dane expected. Instead he crawled back and allowed the others to pass him. Mura thrust his head through the opening and then looked back at Dane.
“I shall have to have help to reach the wall. I am too short-”
He held out his hands and Dane clamped a hold about his wrists. Mura backed cautiously out of the vent and for a moment his weight pulled Dane forward. In that same instant the younger man felt Kosti’s grip about his hips giving him the anchorage he needed as he lowered the steward to the wall.
“Made it!” Mura trotted several feet to the right on the wall and stood waiting.
Dane turned to lower himself to the same level.
“Good luck!” Kosti said out of the shadows. Instead of crouching ready to follow, the jetman had moved back in the tube.
“What do you mean?” Dane asked, chilled by something in the other’s attitude.
“You’ve got to go this next stretch by yourselves, fella,” Kosti returned calmly enough. “I haven’t any head for heights. I can’t balance along on those walls down there-two steps and I’d be over the edge.”
Dane had forgotten the big man’s disability. But what were they going to do? The only way out of here lay across the maze of walls, a maze Kosti could not tread. On the other hand they could not leave the jetman here.
“Listen, boy,” Kosti continued. “You two will have to go on. I’ll stay right here. If there is a way out and you find it, well, then maybe I can make it. But, until you are sure, there’s no use in my going along to foul you up. That’s only good sense-”