Suddenly Keller grunted. He pointed to one of the six television screens which aimed out the length of the tunnel and showed the stars beyond.
Those stars were being blotted out. Something vast moved slowly and deliberately across the shaft they navigated. It closed the opening. Their retreat was blocked. The ship was shut in, in the center of a mountain of stone which floated perpetually in emptiness. Burke checked the ship's forward motion, judging their speed by the side walls shown by the ship's outside lights.
Very, very slowly, faint illumination appeared outside. In seconds they could see that the light came from long tubes of faint bluish light. The light changed. It grew stronger. It turned green and then yellowish and then became very bright, indeed.
Then nothing more took place. Nothing whatever. The five inside the ship waited more than an hour for some other development, but absolutely nothing happened.
Chapter 6
There was a tiny shock; in a minute, trivial contact of the ship with something outside it. Drifting within the now brightly lighted bore, it had touched the wall. There was no force to the impact.
Keller made an interested noise. When eyes turned to him, he pointed to a dial. A needle on that dial pointed just past the figure "30." Burke grunted.
"The devil! We've been waiting for things to happen, and they already have! It's our move."
"According to that needle," agreed Holmes, "somebody has kindly put thirty point seven mercury inches of air–pressure around the ship outside. We can walk out and breathe, now."
"If," said Burke, "it's air. It could be something else. I'll have to check it."
He got out the self–contained diving apparatus that had been brought along to serve as a strictly temporary space suit.
"I'll try a cigarette–lighter. Maybe it will burn naturally. Maybe it will go out. It could make an explosion. But I doubt that very much."
"We'll hope," said Holmes, "that the lighter burns."
Burke climbed into the diving suit, which had been designed for amateurs of undersea fishing to use in chilly waters. On Earth it would have been intolerably heavy, for a man moving about out of the ocean. But there was no weight here. If M–387 had a gravitational field at all, which in theory it had to have, it would be on the order of millionths of the pull of Earth.
Keller sat in the control–chair, watching the instruments and the outside television screens which showed the bore now reduced to fifty feet. Somehow the more distant parts of the tunnel looked hazy, as if there were a slight mist in whatever gas had been released in it. Sandy watched Burke pull on the helmet and close the face–plate. She grasped a hand–hold, her knuckles turning white. Pam nestled comfortably in a corner of the ceiling of the control–room. Holmes frowned as Burke went into the air–lock and closed the inner door.
His voice came immediately out of a speaker at the control–desk.
"I'm breathing canned air from the suit," he said curtly.
There were scrapings. The outer lock–door made noises. There was what seemed to be a horribly long wait. Then they heard Burke's voice again.
"I've tried it," he reported. "The lighter burns when it's next to the slightly opened door. I'm opening wide now."
More noises from the air–lock.
"It still burns. Repeat. The lighter burns all right. The tunnel is filled with air. I'm going to crack my face–plate and see how it smells."
Silence, while Sandy went white. But a moment later Burke said crisply, "It smells all right. It's lifeless and stuffy, but there's nothing in it with an odor. Hold on—I hear something!"
A long minute, while the little ship floated eerily almost in contact with the walls about it. It turned slowly. Then there came brisk, brief fluting noises. They were familiar in kind. But this was a short message, of some fifteen or twenty seconds length, no more. It ended, was repeated, ended, was repeated, and went on with an effect of mechanical and parrot–like repetition.
"It's good air," reported Burke. "I'm breathing normally. But it might have been stored for ages. It's stale. Do you hear what I do?"
"Yes," said Sandy in a whisper to the control–room. "It's a call. It's telling us to do something. Come back inside, Joe!"
They heard the outer air–lock door closing and its locking–dogs engaging. The fluting noises ceased to be audible. The inner door swung wide. Burke came into the control–room, his helmet face–plate open. He wriggled out of the diving suit.
"Something picked up the fact that we'd entered. It closed a door behind us. Then it turned on lights for us. Then it let air into the entrance–lock. Now it's telling us to do something."
The ship surged, ever so gently. Keller had turned on an infinitesimal trace of drive. The walls of the bore floated past on the television screens. There was mist in the air outside. It seemed to clear as the ship moved.
Keller made a gratified small sound. They could see the end of the tunnel. There was a platform there. Stairs went to it from the side of the bore. There was a door with rounded corners in the end wall. That wall was metal.
Keller carefully turned the ship until the stairway was in proper position for a landing, if there had been gravitation to make the stairs usable. Very, very gently, he lowered the ship upon the platform.
There was a singular tugging sensation which ceased, came again, ceased, and gradually built up to a perfectly normal feeling of weight. They stood upon the floor of the control–room with every physical sensation they'd felt during one–gravity acceleration on the way out here, and which they'd have felt if the ship were aground on Earth.
"Artificial gravity! Whoever made this knew something!" Burke said.
Pam swallowed and spoke with an apparent attempt at nonchalance.
"Now what do we do?"
"We—look for the people," said Sandy in a queer tone.
"There's nobody here, Sandy!" Burke said irritably. "Can't you see? There can't be anybody here! They'd have signaled us what to do if there had been! This is machinery working. We do something and it operates. But then it waits for us to do something else. It's like—like a self–service elevator!"
"We didn't come here for an elevator ride," said Sandy.
"I came to find out what's here," said Burke, "and why it's signaling to Earth. Holmes, you stay here with the girls and I'll take a look outside."
"I'd like to mention," said Holmes drily, "that we haven't a weapon on this ship. When they shot rockets at us back on Earth, we didn't have even a pea–shooter to shoot back with. We haven't now. I think the girls are as safe exploring as they are here. And besides, we'll all feel better if we're together."
"I'm going!" said Sandy defiantly.
Burke hesitated, then shrugged. He unlatched the devices which kept both doors to the air–lock from being open at the same time. It was not a completely cautious thing to do, but caution was impractical. The ship was imprisoned. It was incapable of defense. There was simply nothing sensible about precautions that couldn't prevent anything.
Burke threw open the outer lock door. One by one, the five of them climbed down to the platform so plainly designed for a ship of space—a small one—to land upon. Nothing happened. Their surroundings were completely uninformative. This landing–platform might have been built by any race on Earth or anywhere else, provided only that it used stairs.
"Here goes," said Burke.
He went to the door with rounded corners. There was something like a handle at one side, about waist–high. He put his hand to it, tugged and twisted, and the door gave. It was not rusty, but it badly needed lubrication. Burke pulled it wide and stared unbelievingly beyond.