How long would the battery last? A couple of hours? One?
Switch on again. The light hurt his eyes for a few seconds. He looked at the tunnel entrances. Maybe "first left was ambiguous; there were two entrances sharing a larger one. He said, "Oh G.o.d! and crawled swiftly along this other tunnel, using his elbows to wriggle along like a lizard. Why not gamble when you have nothing to lose?
A random walk in two dimensions will eventually take you where you want. It may take a very long time, depending on the number of choices, and the distance to cover, and luck. But you will always, sooner or later, emerge from a maze, provided you havent died of cold or thirst in the meantime. In two dimensions, all roads lead to Rome.
This tunnel was even narrower than the last one. It went on for ever.
A random walk in three dimensions is different. In a three-dimensional maze, the probability that youll end up where you want is about Petrie tried to remember the exact figure 0.35, thats it, one in three.
Im going to die here, right inside one of my knots.
McCrea and Whipple, that was it. Proceedings of the Royal Society of Edinburgh, 1940. The n.a.z.is were about to invade Britain and these cool dudes were calculating random walks, like playing bowls with the Armada on its way.
After ten minutes he thought to give up, crawl backwards! back along its length. Something stupidly jumped into his head: It may be proper likewise to mention to the benighted traveller, that when he falls in with bogles, whatever danger may be in his going forward, there is much more hazard in turning back.
R. Burns, footnote to Tam OShanter, 1710 The tunnel curved slightly to the right, giving him a ten-metre line of sight. He would crawl that distance and then give up.
Ten metres on, the tunnel seemed to be opening out. He gave it another ten, and then twenty, and then the torchlight was showing a large chamber strewn with boulders. Reaching it, he found it was about nine feet high and adorned with thousands of little needle-like stalact.i.tes and stalagmites. He stood up and stretched.
Leading off from this chamber was a curving man-sized tunnel. If he wasnt lost, and if Svetlanas map was right, this would lead to Tysons Autobahn.
It did, and Petrie almost wept with relief. He shouted, "Yes! and, "Yes! Yes! Yes! echoed back at him, fading into silence.
The Autobahn, an ancient bedding plane uplifted by whatever forces had created the Tatras, was a lot steeper than he had expected it to be. It was about twenty metres broad and ten high, patterned with stony icicles on floor and roof, many of them as thick as tree trunks. It stretched beyond the range of Petries lamp.
Again he momentarily switched off; again, pitch black. Freya! Where are you?
A kilometre, Svetlana had said. He set off smartly, his breath echoing in the long chamber. Gradually, as he climbed, the roof became lower. He thought he glimpsed ...
Voices!
Petrie froze, switched off his helmet lamp and stood in the pitch black. Not pitch black. Lights, at the foot of the Autobahn. Half a kilometre away, but it was hard to judge distances.
A candlelit procession. Skiers gliding down a piste, torches lighting the snow. A Viking funeral.
None of these. Men with guns, hunting him.
He switched on his lamp, turned to run.
Men shouting, the tunnel efficiently transmitting the voices so that they seemed only yards away.
Bullets would follow. Petrie began to swerve, keeping big stalagmites between him and his pursuers when he could. The ground levelled and sloped down; another fifty metres and he would be out of sight. A smattering of gunshot and little chips of limestone buzzing off stone icicles. One of them hit him hard on the cheek, drew blood. A last swerve and he was running downhill and there it was, seven metres down a shaft, the sump, a turquoise pool of infinite depth with a red nylon rope descending into it, attached to the vertical rock by pitons, and demons waiting for him under the smooth surface.
Petrie stared, horrified, at the water, still as death. Nothing was going to induce him into that pool.
Ah, Tam! Ah, Tam! thoull get thy fairin! In h.e.l.l, theyll roast thee like a herrin.
A shouted command. They were much closer. Or was it the acoustics? Petrie scrambled down, gripping the rope, slipped, cried with pain as the friction burned the palms of his hands. Then his ankles were into the icy water, and his waist and his chest. He took a deep breath and then his head was under and he was hauling himself along clumsily, upside down, water getting into his nose.
He made no attempt to time the underwater journey. He didnt try to estimate how far the sump went down. But it levelled at some depth and he was pulling himself along frantically, his helmet b.u.mping against the rock. He wondered if Freya had gone much further along the sump, whether he would b.u.mp into her drowned body. Stars began to explode in his eyes. Random walks, knots, soldiers, Freya, Hapsburg castles, alien signals, all went from his mind and were replaced by a single, burning focus: the red nylon line, winding through branching tunnels. And then the rope was curving upwards and there was light and he broke the surface, whooping and gasping.
Freya was perched on a boulder, looking like a sodden elf. Her helmet torch dazzled him.
"You took your time, she said.
He heaved himself on to a ledge, flopped out on it for a few seconds. Then he sat up, still gasping. "Theyre on the Autobahn. They shot at me.
Freya scrambled around, picked up a fist-sized rock and started to hammer at a piton. Petrie, weak at the knees, scrabbled around for another stone.
"Tom, someones on it.
The rope had gone taut, as if a fish had been hooked on it.
Petrie said, "Jesus.
But now the piton was loose and in a minute they had the grim satisfaction of seeing the guide rope spiral down towards the bottom of the sump. Petrie felt a surge of guilt at his own hope that the soldiers using it would drown.
And now they were in a cavern with limestone stalagmites the size of tree trunks and branches leading off like exits from Piccadilly Underground.
"I know the way, Freya said. "Ive been along it. She led Petrie, streaming water, along a high tunnel, through a knee-deep stream. Ahead, faint light was scattering off the tunnel wall. They switched off their lamps. Human chatter began to echo. And then there was a short, dry shaft, brilliantly lit from the other end. Freya put a finger to her mouth and crawled along it. Petrie followed, and found himself looking down into a vast natural cathedral with flowstones, fountains and millions of stone icicles, frozen in brown, white and orange limestones. The cathedral was glowing from the spotlights scattered around its walls. About twenty people were cl.u.s.tered round a guide.
"This is the second party Ive watched, Freya whispered. "I think the woman at the left is there to pick up stragglers.
"Wait until theyve moved off, then catch up, with apologies. If anyone asks about our clothes, weve been scuba diving.
But Freya, scanning the cavern, seemed not to have heard.
"Freya, we cant hang about. There could be strong swimmers amongst the soldiers. We may only have a couple of minutes start. He looked back fearfully at the black hole of the sump.
"I hope they all drown, she hissed. Then she cuddled into him like a little wet kitten and whispered, "Isnt this beautiful? and Petrie tried to suppress a fit of giggling hysteria.
35.
Death Squad Gibson shambled reluctantly into the refectory. The entire team was present and the table was laid with toast, hard-boiled eggs, b.u.t.ter and jam. The croissants looked and smelled fresh, but only Shtyrkov was eating. Gibsons face twisted in tension, but only for a moment. Svetlana poured him a coffee.
"Cant be long now, Charlee. Shtyrkov was grinning and Gibson believed that the man had finally lost his mind. "Not once they find Hanning has failed to deliver.
"I looked further down the signal, about two minutes into it, using Toms algorithm and found another genome, would you believe it? Another billion bytes or so. Gibson was speaking without enthusiasm. "It doesnt match anything in the snp database.
"Meaning? Shtyrkov asked.
"Its definitely non-human. Not even primate.
"Drosophila? Nematode?
Gibson shook his head emphatically. "Its far more complex. Whatever it is, its biologically more advanced than anything on Earth.
"More complex equals superior?
"Put it this way. Until I knew more about this ent.i.ty, I wouldnt want to meet it on a dark night.
Svetlana pushed her uneaten egg away, an angry gesture. She was close to tears. Shtyrkov squeezed her hand.
Gibson said, "I know. Here we are, frantically working to the last minute for the good of all mankind, and mankind is about to squelch us.
Shtyrkov asked, "I wonder how theyll do it? He seemed detached, almost cheerful.
"Why dont we just open the door and run out? Svetlana asked.
"Calm yourself, child.
Gibson sipped his coffee. It was the best he had ever tasted. Every sense was tingling. He wondered if this was what Shtyrkov was feeling, or whether the temporal lobe stuff was finally getting to him, or whether it was just his impending execution. "They dont give the n.o.bel Prize posthumously.
"Charlee Gibson. For once in your life forget earthly baubles. This discovery is beyond any prize. Shtyrkov raised his coffee cup to Gibson. "You are a very imperfect man, Charlee, but you have done something wonderful. Your reward is immortality.
"I hope Tom and Freya make it, said Gibson. "I want my immortality.
36.
Pursuit Sibelius filling the cathedral, scattering off a million stalact.i.tes, echoing along a hundred tunnels. A pool glowing blue from hidden underwater lighting. The tour guide had stopped and was talking to his audience. Freya edged her way forwards. A mother with a child said something in German; some joke, Petrie inferred, about their sodden clothes.
And the guide was still talking, over the music.
Petrie looked behind, trying to hide the fear, make it seem like a casual glance. The path they had come down was a giant orange throat lined with needles. There was no sign of pursuit. Not yet.
And the guide was still talking.
At last there was a flurry of laughter, and a little applause, and the inspirational music had risen to a shattering climax and stopped. Now the crowd was shuffling with infinite slowness towards concrete stairs which headed up towards the roof of the cavern.
Freya was well ahead, just a few bodies behind the guide. Petrie was almost taking up the rear. In a minute she had vanished from sight. And then at last Petrie was at the top of the steps. If the Slovak army was waiting there was nothing to be done. Along a short corridor, and out, and blinking in the white glare of snow. A hairpin path plunged steeply down towards roofs far below, just glimpsed through trees. There were no soldiers to be seen. Freya was waiting, letting the crowd flow around her, wet blonde hair over her shoulders. At that moment Petrie believed she was the most beautiful woman on Earth.
The path was slippery and people linked arms or gripped the steel handrail as they started the descent.
The guide locked the exit door. It was sheet metal.
Freya put her arm in Petries and they started slowly down. The snow had compacted to a shiny, hard surface. The guide and the tail-end Charlie were soon ahead of them, striding down the slope with practised ease.
And now the fugitives were alone.
"What now? Freya wondered.
"Were alive.
She was gripping his arm. "I wonder about Charlie and Vash and Svetlana.
Petrie looked back at the door, still only metres from them. "Its solid steel. The soldiers are entombed. Even if they found their way back through the Wormhole, theyd never get upstream against the Styx.
"They have guns. If they get through the sump theyll shoot the lock, like they do in movies.
Petrie looked again at it, wondering. "Theyll never get through the sump.
Freya said, "Youre shaking. Are you cold? She held him. For a few glorious seconds he felt her b.r.e.a.s.t.s, warm and wonderful, against his chest.
Then he gently disengaged himself. "No, Im terrified. Lets clear off. By now the army have worked out that were either trapped inside the mountain or weve found a way out of it.
They clambered down the path, gripping the handrail, and then left it, ploughing through the snow-deep woods in case of soldiers at the foot of the path. A big fluffy s...o...b..ll loped down through the trees and pa.s.sed them at a leisurely pace, gathering speed: a gentle warning that they were at risk from avalanche. On the flat, they crossed a wooden bridge and an icy stream. A large yellow notice told them they had left the Demnovsk Cave of Liberty. And they were now on an ice-covered road winding perilously through steep-sided mountains.
There was a general exodus in progress, cars with snow-chains and skis on their roofs moving slowly down the valley to their right, heading for home after the weekend skiing.
Right was motorway, and the road to towns like Popov and Levoce where you could lose yourself.
Right was the border with Poland, not too far to the north, with big cities like Cracow and Wroclaw in easy reach.
Right was the only sensible way to go.
They looked at each other, and without a word turned left, against the flow.
Nerves taut and chilled to the bone, they spied the land from trees at the edge of a car park. The nearest humans were two hundred metres away, but still Petrie spoke quietly. "Are you thinking what Im thinking?
Freya gave a tense little nod.
Petrie watched the activity quietly. "Want to chance it?
At five in the morning, the big foyer of the hotel was buzzing with life. Two blue tourist coaches stood outside the entrance, engines throbbing steadily, steam coming from their exhausts. Bleary-eyed people, dressed against the cold, were boarding them in twos and threes. The driver was heaving skis and suitcases into the bowels of the first coach, showing every sign of a short temper.
"We cant do this, Freya said.
Petrie murmured, "What else is there? Climb over the mountains?
"We have no luggage, no skis. And theres bound to be a tour operator.
"Well just have to slip past.
Freya shook her head. "Tom, thats crazy.