Tess was flying a little ahead of Kevin, and below him, but he was within her field of vision constantly. All of a sudden, there was a wobble and a flutter of darkness where he had been, and then she was on her own in the swirling snow. She wheeled in a great arc and turned back to see a black drake with a green head flapping towards her as fast as its little wings would carry it. Tess understood. Two albatrosses landing on the Liffey would undoubtedly cause a little more attention than they wanted.

The long spell of cold weather had caused parts of the river to freeze over, even before the snow had started to fall, but a channel through the middle had been kept clear by the current for most of its length. If anyone had been watching, they wouldn't have been too surprised to see two ducks coming in to land and floating along downstream for a while. They would have been a little more surprised, however, to see both ducks dive, one after another, and not come up again.

High above the Polar ice cap, Lieutenant Andy 'Scud' Morgan was flying a medium-range bomber with a full complement of armed missiles. The plane was on loan from the Pakistan Air Force, who had bought it from its manufacturers in the USA some nine months earlier. He checked the radio link with ground control to make sure that he wasn't being overheard, then he said: 'At least it doesn't smell of curry.'

'Huh?' said his co-pilot, Mark Hadders, who was sitting in the seat behind him.

'No garlands round the control panel. No incense burning under the seats.'

'Huh?' said Hadders again. He was cleaning his fingernails with a tooth broken from a pocket comb. The comb had about twelve teeth left. Scud Morgan hated Mark Hadders more than anyone on earth. He hated Mark Hadders more than he hated the Russians or the Iraqis or even the Cubans. Mark Hadders was a numbskull. Scud didn't know where he had got the nick-name 'Squash', but he was willing to take a good guess. The only part of Hadders' brain that worked was the bit that handled the aeroplane. The rest of it was completely atrophied.

But he had to talk to somebody. 'They didn't use the plane to clear some of their homeless off the streets,' he said, more loudly than he needed to.

'Why should they?' said Hadders. 'We don't. Besides, I think they're mostly Muslims in Pakistan. They don't go in for the incense and garlands stuff.'

'Dumb a.s.shole,' muttered Morgan.

'Huh?'

'I said, "some h.e.l.l-hole". Down there.' He pointed down at the floor of the c.o.c.kpit beneath his feet.

They were flying above the storms, in bright sunshine. Beneath them there was nothing but unbroken cloud for mile after mile after mile.

'Anything on the radar, Jake?' said Morgan. The technician was behind them in the body of the plane, dozing over a bank of specially installed surveillance equipment. 'Couple of planes,' he said. 'That's all.'

'Theirs or ours?' There was no answer, so he said: 'Ha ha. Theirs or ours. Joke.'

There was still no answer. Hadders had finished cleaning his nails and was reading another of those dumb books that he seemed to go through like comics. Morgan had tried one once, but it made no sense at all. It was by some British woman who had been dead for a hundred years and whose brain had been dead for a hundred and fifty.

'They think we're crazy, you know?' he said.

Hadders sighed and rested his book on his knee. 'Who, Andy?'

'The Pakistanis, the Israelis, everyone who's cleaning up by hiring our own airplanes back to us.'

'No they don't, Andy.'

'Sure they do. And they're right, aren't they? We got sixteen hundred planes in the air, day and night, dodging each other like a swarm of mosquitos, and what are we fighting? A snowstorm.'

'Don't worry about it, Andy. We're not doing anybody any harm. Let them think what they like.' He picked up his book again.

'But I wasn't trained to not do anybody any harm!' said Morgan. 'I wasn't trained to spend eight hours a day pretending to be a weather satellite!'

'Come on,' said Hadders. 'Look around you, Andy. The sun is shining in a clear blue sky. At least we're not down there wearing snow goggles and dodging polar bears.'

'Anything would be better than this,' said Morgan. 'Sitting up here and getting bed sores on my rear end with some lunatic who reads ... what do you call that stuff, anyway?'

'Literature,' said Hadders.

'h.e.l.l, that ain't literature!' said Morgan. 'Literature is what they give you when you can't decide which hi-fi system to go for. I got piles of it at home.'

Hadders wasn't listening. He was mentally absent again, reading his book.

'Anything new, Jake?' said Morgan.

'Couple of planes,' said Jake.

CHAPTER SIXTEEN.

GOATS HAD THE SECRET of mischievous fun, it was true, but the spirit of pure joy had been perfected by another species and made its own. Two of these creatures were now speeding down the River Liffey, keeping well below the surface except when they had to rise, briefly, to catch air. They were dolphins, and they were heading for the open sea.

There are other sea creatures as fast as dolphins, but there are none that enjoy their speed so much. There are other sea creatures that live among their own kind, but there are none that take so much pleasure in each other's company. And on land or sea, there are no creatures anywhere that get such enjoyment out of merely being alive.

Tess and Kevin sped downstream, catching the strongest currents to help them on their way. They stayed close together, weaving around bridge supports, making small detours to get a quick look at interesting bits of wreckage on the river bed. There were prams, bicycles, supermarket trolleys, there were sunken boats, and cars, and once they pa.s.sed a bus, with its rows of silted windows gazing vacantly towards the surface.

Tess knew that if she had to choose now, she would not be a cat. There was nothing that compared with being a dolphin. Her awareness was acute, her intuition sharp, and her body flowed with the current, all comfort and sinuous strength. If there had been time, she would have stood on her tail in the water and laughed at the people crossing O'Connell Bridge or walking to work beside the river. She would have done it not because she wanted their attention and applause, but because joy, more than anything else in the world, is for sharing.

Many, many miles away, between Norway and Iceland, the nearest krool was sliding towards them along the top of the rapidly expanding ice cap. It knew nothing of dolphins, and nothing of joy. All it knew was cold, and an endless, relentless hunger.

From above, the krools were invisible. They were round and shallow, roughly the shape of an upturned saucer, and so huge that they could cover an average-sized town without leaving any trace of it. Because they were very much colder than the snow around them, it didn't melt when it landed on their backs, but gave them a coating of camouflage. So perfectly did they blend into the surrounding snowfields that they could not be seen at all, even when they were moving, unless you happened to be right in front of them.

And if you were, you were in big trouble. For krools will stop at nothing when the time comes around to expand their icy kingdom across the globe. They will slide over land or sea on the carpet of ice that they spread for hundreds of miles before them with their snowy breath, and as they travel they will eat anything of animal or vegetable origin which lies beneath the snow or above it. Trees, rocks, houses, and all the ice and snow which cover them, are swept into the great maw of the krool and processed by its phenomenal digestive system. It sifts out what is useful and discards what is not as a powdery mixture of ground ice and stone. And the more it eats, the larger and colder it becomes.

The only enemy the krool fears is heat. Even a small animal which might somehow survive the vanguard storms by burrowing a hole in the snow can cause a reaction of revulsion in the krool as it pa.s.ses over, and give it a spell of indigestion. The heat of the drilling rig had enraged the krool who encountered it, and caused it to heave and shudder for several days before it regained its strength and went on.

Such instances, however, are rare. The krools give fair warning of their arrival, and those warm-blooded creatures who are unable to keep pace ahead of the storms are usually frozen corpses by the time the krools arrive.

At the mouth of the River Liffey, Tess and Kevin turned east into the Irish sea, then northwards up the coast. They stayed close to the sh.o.r.e, where the water was warmer, but even so it soon became clear that they would need more insulation than they had to cope with the cold seas ahead of them. There was only one possibility for a journey as long as the one they were about to undertake and, reluctant as they were to change out of dolphin form, they knew that they would have to.

The oceans, as any seaman will testify, exist in a different part of time from the land. If anyone were to ask Tess how long her journey through the Irish Sea and up into the Norwegian Straits took her, she would have been unable to answer. How long is an hour? An hour doing homework or an hour at the fun-fair or an hour when you're too sick to go out and play? How long is an hour for a whale? For the whole of that trip beneath the waves, time was a currency without value, as meaningless as pound coins are to a frog.

Tess's human mind was all but engulfed by the phenomenal intelligence of the whale, and it was as much as she could do to keep her purpose intact. Whales have a knowledge of the whole global ocean with its varying currents and temperatures and moods, not as a person remembers some place where they have been, but as they might know their own house or garden, without ever having to think about it. But more than that, they could know each part of their immense home and what was happening there, even though they were not in it, for the voices of whales travel far and their thoughts travel further.

This much Tess might have been able to remember, but it was only the tattered and tawdry edge of the truth, the way that words can only explain the edges of dreams and not their vivid depths. The whole of that world could not be held in the limited mind of a human being, and was lost to her forever when the time came to leave the oceans behind. But the thing that Tess never forgot was the whales' code of honour. For the whales know the ways of the ocean from top to bottom and from end to end, and that means that they know where the whaling boats lie. It is not stupidity which makes whales easy prey for the gunners, but their knowledge that the ocean is their own, and that it is better to die than to move even by the width of a flipper towards the faint-hearted existence of the hunted.

Krools move with astonishing speed when they first wake up. The areas of the planet which are near the polar regions have no resistance to their advance, because they are affected by the presence of the krools even as they sleep. They are territories which are already claimed by the cold and merely need to be re-established.

As they move towards the equator, however, their progress slows, partly because they come into contact with the sun. By the time these krools had reached the line of sixty-five degrees lat.i.tude, which runs through the middle of Norway and Sweden, and through Siberia, Alaska and North Canada, they were already slowing down. Their snowstorms still preceded them by hundreds of miles, but would spread more slowly as they blew towards Southern Europe and the USA.

The krools on the Norwegian Sea were having a particularly hard time of it. They had long since pa.s.sed the limit of permanent pack ice and were having to use enormous reserves of cold to freeze the surface of the sea before them as they went. It was a hungry time for them as well, because there was no nourishment to be had from the sea, whose citizens stayed well below the freezing surface. All krools are dangerous, but a hungry krool is the most dangerous of all.

CHAPTER SEVENTEEN.

WHEN TESS AND KEVIN reached the fresh edge of the ice cap, now lying between Iceland and Norway, they said goodbye to the world of the whales and turned themselves into seals for their re-emergence on to the surface.

Despite their layer of blubber, they were shocked by the intensity of the cold. Snow was still falling, but it was a very different kind of snow from the large, soft flakes which were still settling on Dublin. Here the particles were small and dense, as though the air itself were ice that had lost its solidity but nothing of its coldness. It froze their whiskers as soon as they flopped out of the sea, and it stung their nostrils and eyes.

Tess stood beside Kevin, both of them blinking against the swirling snow and wondering what to do. Her mind searched for possibilities, but there were only two. To turn back, or to go on. It was Kevin who made the decision. He touched her nose briefly with his, and began to shuffle himself forwards. Tess followed.

But seals are c.u.mbersome on land, and unhappy. Their exertions warmed them but they were making little headway. After a while they stopped to rest, but as soon as they did, the cold began to bite into them again. So they moved on in a more effective manner, as polar bears this time.

Tess was torn between conflicting instincts. She wanted to turn back, to the solid safety of whales and dolphins and home, but at the same time she was afraid of being separated from Kevin in this white and terrifying world. She knew that nothing would persuade him to give up, even though she had long ago forgotten the feeling that had made her understand why. She had the awful sensation of being caught up in his life, his search for some intangible thing which she neither understood nor wanted. It made her feel helpless and worthless, with no choice but to trail along in his tracks and accept whatever was going to happen.

And there was only one thing, as far as she could see, that could happen. They would walk into the snow and ice until they could walk no longer, and then they would die. She wondered what had happened to the other polar creatures, the bears and Arctic foxes with their silver coats, and she hoped that at least some of them had managed to stay on land and keep ahead of the storms. She shuddered and shook a crust of snow from her coat. Her fur was thick, but not thick enough, she knew, to protect her for much longer.

Kevin was still walking with silent determination, but the snow was getting deeper as they got further from the edge of the ice, and it was soft and powdery, which made progress slow and tiring. Tess's eyes and lungs were sore from the bitter air. She dropped her head. White bears, white snow, white air constantly moving around them. The only change in all that whiteness was when, from time to time, Kevin turned around to make sure she was there, and then she saw his black nose and eyes.

It was almost a relief when night began to fall. To Tess, numb with cold and exhaustion, it no longer seemed to matter what form rest might take, as long as it came soon.

Kevin stopped. Directly in front of them was a miniature mountain, an iceberg which had been captured and imprisoned by the spread of the krools' carpet. Some of its facets were too sheer for snow to lodge there, and the ice showed through, darkly opaque, like crystal. To Tess it represented an obstacle, but to Kevin it was a G.o.dsend. Because around its base the snow had gathered into wide, deep drifts. He began to dig.

In the middle of the night, Tess woke. It was absolutely dark in the snowhole. If any moon or starlight filtered through the clouds above, it failed to make its way through the tunnel they had dug and into their tiny cave.

It was surprisingly, luxuriously warm in there, from the trapped heat of their furry bodies. Tess would have stretched if there had been room, but they had made the s.p.a.ce just big enough for the two of them to sleep curled up, so that they wouldn't have to warm any extra air. She yawned and turned over so that she was facing Kevin, and now she realised why she had woken. It was a long time, who knew how long, since she and Kevin had talked together, and she wanted to do it now before daylight came and urged them into action. She Switched, and immediately felt a little frightened to be lying in total darkness with a large bear. She could smell bear fur and bear breath, and before it frightened her any further, she reached out and tugged at Kevin's thick, warm coat.

He started, then grew rigid, and then the coat between her fingers was cotton, a little damp.

'You idiot, Tess! Don't ever do that again!'

'What? What did I do?'

'I was a bear, you fool. You woke me up. I nearly ripped out your throat!'

'Wow.'

'I only just remembered in time!'

'Sorry,' said Tess.

Kevin said nothing, but turned awkwardly in the cramped s.p.a.ce until he was on his back. Tess was afraid that she was going to cry and, as if he realised, he reached out his hand and touched her arm.

'It's OK,' he said. 'I shouldn't have shouted. I'm sorry.'

Tess turned so that she was on her back as well and their shoulders were squeezed tight against each other in the dark. For a long time they lay in silence breathing the warm, foetid air.

Tess's mind was a jumble. She knew that the most sensible thing to do was to turn back and go home, but she couldn't say it to Kevin. It would seem like a betrayal after they had come so far. And if they weren't going to go back, what did you say to someone when it might be your last conversation with them? There was an awful sense of the executioner's cell about the snowhole. And despite all they had been through together, Kevin seemed like a stranger again, lost in his own thoughts. But it was he who spoke first.

'What did she mean, Tess?'

'Who? Lizzie?'

'Yes. About what isn't?'

'I don't know.'

'But what could she have meant? It must have been important or she wouldn't have said it.'

'I don't know if that follows,' said Tess. 'Lizzie said an awful lot of things that weren't important.'

'Oh, come on, Tess. You're not going to start backing off again, are you? It's hardly time for it, you know.'

'Maybe it is the time for it. Maybe it's the only time. The last chance we have.' She expected him to be angry, but his answer was surprisingly calm.

'No, it's too late for that now. We've come this far because we believed what Lizzie said. It'd be completely pointless to give up now, just when we're getting to the heart of it.'

'The heart of what?'

Kevin shrugged, and they were squeezed so tightly together that Tess's shoulder rose with his. At another time she would have laughed, but at that moment laughter seemed to belong to a different life.

'Of what we are, I suppose,' said Kevin. 'Of survival, of freedom, of independence.' He sighed. 'But I don't know what the problem is. My mind feels as if it's shot through with steel cables, or something. Whenever I try to think about anything a bit different, like what isn't, I just find myself running along the same old lines. I can't seem to get anywhere.'

'I suppose we haven't done too badly so far,' said Tess, 'and most of the things we've done have been your ideas. The dolphins and the seals and the polar bears and this hole in the snow.'

'Yes. But it's all practical stuff, isn't it? It's all what is and not what isn't. But the polar bears aren't going to take us much further, are they? We couldn't last much longer out there, and we can't hole up for ever, either. We need something else now. Some leap of imagination.'

He fell silent again. Tess noticed that her eyes were flicking around in the darkness, seeking something to rest upon. She closed them, and must have dozed for a moment, because Kevin's voice woke her from a dream.

'Have you got your watch on?'

For some reason the dream was important, but when she tried to remember it, it slipped away from her. It was all snow, anyway, ancient and endless. She felt her wrist. 'Yes.'

'Has it got the date on it?'

Tess was already looking at it. 'It says seven-thirty,' she said, 'but I suppose the time is different up here. I can't see the date. That bit isn't luminous. Why do you want to know, anyway?'

'I was just wondering when my birthday was. It must be quite soon.'

'What date is it?'

'The thirtieth. Can't be that far off now.'

Suddenly Tess realised why he was asking. She had an awful image of Kevin losing the ability to change and being stuck out there in the frozen wastes. He would freeze in no time in that stupid parka. He didn't even have gloves. And going back would be just as dangerous. He might be in the middle of the sea when it happened, or up in the air. It was important to know.