After a moment, he heard Dallas speaking calmly.
‘It’s okay,’ he said. ‘You can get up now. It’s quite dead. My last shot must have turned it as it was getting ready to fire. I probably dislodged something when I touched it just now.’ Dallas surveyed the scorch mark on the wall where Cavor had been standing. The area looked as if it had been struck by lightning. ‘It’s as well you moved when you did. Otherwise you wouldn’t have had to worry about radiation sickness.’
‘I’ll try to remember that when I’m puking my guts out.’ Feeling that it was now safe to turn up the illumination of his computer, he added: ‘In less than one hour and fifty-eight minutes, according to your original estimate.’
‘Then we’d better be on our way,’ said Dallas, consulting his own computer. He paused, and then cursed. ‘Shit.’ He tapped the computer irritably. ‘Must have happened when the robot fired that bolt of electricity,’ he said. ‘Some kind of electromagnetic pulse, perhaps. Part of the high voltage seems to have been deposited in my computer. The components are working, all right. And my life-support systems are working okay. But there must have been a transient malfunction in the digital logic circuits.’
Cavor looked at his own computer again. ‘No problem. Mine’s working perfectly.’
‘That’s fine,’ Dallas said sheepishly. ‘Except that you don’t happen to have the directions to the labyrinth loaded into your computer’s memory.’
‘Why the hell not?’
‘It’s started again. Will you look at that?’ Dallas was reading the fault diagnosis that now appeared on the screen of his computer. ‘The computer got browned out by an energy value of just a few watts. Hardly anything at all. My God, this thing’s sensitive.’
‘So am I, Dallas. Call me a coward but leukemia has that effect on me.’
Dallas switched on the halogen headlamps located on each side of his helmet and threw down his infrared flashlight.
‘There’s no need for us to stay on infrared now,’ he said. ‘Even if we don’t know where we’re going, at least we can see that we don’t.’
‘What do you mean? Your computer’s working again, isn’t it?’
Dallas watched the machine reset itself, with the labyrinth directional program starting at the beginning again. ‘Yes, but only from the beginning,’ he said. ‘But we’re already about a third of the way along the route and there’s no way of telling precisely where we are. Order just became chaos again.’
‘Can’t we find our way back to the beginning and then start afresh?’
‘That might take as long as going forward. Fact is, we’re lost, Cav.’ Dallas looked at the robot. ‘I guess we won’t forget we’ve seen this particular junction, anyway.’ He started down along the next corridor. ‘There are some compensations to be had. We already know that a center does exist. Many labyrinths don’t have one, of course. We know the kind of labyrinth we are in: multicursal as opposed to unicursal. We can see properly — the point of the darkness was to conceal the very existence of a labyrinth from the interloper. Moreover, we need only find a way in, and not out. Our exit will be taken care of by the Descartes computer. As soon as the vault door has been opened, Descartes will assume an emergency has occurred and discontinue all normal security measures. We’ll be able to ride out of here on board the electric car, as if we had two first-class tickets.’
‘If I didn’t know you better, I’d say you were enjoying this.’
‘If I didn’t know better, I might agree with you.’
XIII
At every junction, Dallas fired his UHT at the wall of the route they had taken, so that a hot spot glowed there like a live coal, a sign to mark the progress of their route, or lack of it; for sometimes they encountered the glowing mark again, whereupon Dallas would scorch the wall with two more marks.
‘We must only choose a route with a single sign or none at all,’ he sighed, exasperated, and obliged them to retrace their steps. ‘And never choose a route with three.’
For almost an hour it seemed to Cavor that they wandered bewildered, entrapped in the coils of the labyrinth that surrounded them. Just as Dallas was about to concede he had been defeated by his own ingenuity, they had an immense stroke of luck. One minute Dallas was cursing the diabolical circuitry of his apparently impenetrable maze, and next he was down on his knees, laughing and rubbing the palms of his gloves on the steel floor. Cavor thought him merely mad, and it was a moment or two before he perceived that the laughter he heard in his headset was born of relief rather than frustration.
‘What?’ he asked, desperate for good news. ‘For Christ’s sake, Dallas. What is it?’
Dallas pointed to the floor. ‘Look,’ he said, still laughing with delight. He rubbed his gloves on the floor again and then showed Cavor the grime-covered palms.
‘Dust,’ said Cavor, unimpressed. ‘That’s just great, Dallas. They need cleaners in here. Maybe we can apply for the job, if we’re still alive, that is.’
‘Don’t you see? Look, you can even see the tire marks.’ He pointed along the floor to a set of tracks leading down one of the corridors. ‘The electric car has been this way. We can follow its trail. What a stroke of luck. When we landed, our engines must have blown some moondust onto the landing site road, otherwise this dust would not be here. We can follow these tracks all the way to the vault.’
Cavor nodded wearily, too tired to say anything, and helped Dallas to his feet.
‘Who needs a golden thread, when we have the Moon to guide our footsteps?’
Their way was quicker now, and except for the need to keep both eyes on the ground for the faint evidence of the electric car, Dallas would have bounded through the remaining corridors.
Suddenly the labyrinth ended in a great smooth and circular wall of dark steel.
‘What’s this?’ asked Cavor. ‘Another hazard?’
‘This is it,’ Dallas told him excitedly. He took Cavor by the arm and led him up to the perfectly smooth curvature. ‘This is the vault, my friend. We’re here.’
Cavor stared up at the giant-sized edifice, astonished at its enormous proportions.
‘We’re here,’ he repeated dumbly. ‘My God, it’s huge.’
‘Of course it’s huge. Did you expect people to take so much trouble to protect some piffling steel box in a wall? The vault is over two hundred feet in diameter. There’s over twenty million liters of frozen blood in there. Think of that, Cav. That’s enough life force to cure an entire country. What a pity we can only take a mere fraction of that. But first — first, you have to open the door.’
‘What door? I don’t see one.’
Dallas pointed at the faint tire tracks that led seemingly straight through the great steel wall.
‘You’re looking at it,’ he said. ‘Thirty-seven inches thick, no exterior parts. No handles, no knobs, no combination bezels, no grips, no spinners, no cranks. All interior mechanism, controlled by Descartes from the inside. There’s no way this door can be opened from the outside, not even if you and I were the president of the First National and the director of Terotechnology standing here.’
‘Then how are we going to get in there? Even a phantom limb’s not long enough to reach through a thirty-seven-inch-thick steel door. It may be a phantasmagoria, Dallas, but it’s no longer than a real arm, of that much I’m sure.’