She rounded the side of some large, inexplicable complex of ancient machinery dented in now by a blind charge of the intruding thing, and came on another working party in the centre of which her grandfather was standing. She stopped, knowing he would be angry if she tried to interrupt what he was saying for anything as trivial as food and drink.

Resting the heavy canister, still more than a one-arm burden, on a convenient support, she stared at the time-worn face of the grizzled old man, heard his harsh words echo away under the deformed curve of the roof.

“Now I’ve had reports already from Clagny,” Grandfather stated. “He went on directly after dawn, and lost the thing’s trail a couple of miles out, among the East Brokes. It might be lairing up there to lick its wounds. If it is, the chances are against it returning to the same side of the Station, but in favour of it coming back sooner or later-the current count for returns runs about six to four runaways. If we’re lucky, it may pick up the Eastigo Creek and work its way downstream, in which case we’ve seen the last of it. Nestamay!”

The girl gave a start. “Y-yes, Grandfather?” she said in a thin voice.

“How do I know it probably won’t follow the creek?”

Nestamay gulped. Grandfather was forever playing this kind of trick on her-shooting unexpected questions in public and demanding an answer that would shame the hearers. He was obsessively proud of the fact that his family was the only one in living memory to add significantly to the traditional stock of Station lore. Sometimes Nestamay wondered if it had been as a by-product of that well-founded pride that her father, whom she barely remembered, had been persuaded to undertake his foolhardy journey away from the Station and off into the vast unknown-the journey from which he had never returned.

For a long moment she stood confused. Then a stir of memory came to her aid. Something acrid about a scent which she had detected drifting into the air of the office late last night, when the thing had been driven away …

“The smell!” she said, suddenly positive she was correct. “When the heatbeams seared it, the smell it gave off didn’t resemble the smell of a water-seeking creature!”

Grandfather looked surprised for an instant. “Very good,” he said. “Anybody else spot that?” His fierce, bloodshot eyes swept the members of the working party. “No? Aren’t you ashamed of yourselves? Here’s my granddaughter, only a few weeks past adulthood, knows it as well as I do, and you lot with all your combined years of experience have to be told! She’s perfectly right-the stink that comes off when a heatbeam hits a water-seeker is heavier, damper, a little sweetish at the back of the throat. The smell we got last night was acrid, dry, and eye-watering.”

He paused. Nestamay, relying on the momentary favour she was enjoying, caught his attention and indicated the refreshments she was bringing; a curt nod gave her permission to distribute them, and she proceeded to do so while he resumed his diatribe.

One or two of the men, dipping their hands in the bag of bread, looked dismayed as they felt its hard stale texture, and shot accusing glances at Nestamay as though to blame her for its condition. A little resentfully, she glared at them.

“Any idea how much power we used last night? There wasn’t anything left for the ovens this morning!”

That didn’t make them any more pleased, of course. Glancing skyward through the rents in the Station dome, they could see the cloudy sky which meant the recharging of the power storage cells would proceed extremely slowly today. Everything at the Station was so interlocked, Nestamay reflected; when a dangerous thing hatched, power had to be set aside for heatbeams or activating electrofences, which meant food became short, or had to be eaten cold rather than hot, clothing due for recycling had to wait no matter how dirty and torn it had become, and at night the people had to huddle together against the chill …

She served the last of the working party with his cup of broth and hunk of bread, and prepared to move on. Once again Grandfather interrupted her.

“Nestamay, don’t forget I’ll want to see you this morning. You’re due for a test on last week’s instruction!”

Nestamay nodded. She’d hoped Grandfather might be too preoccupied with the emergency to remember, for she was very tired now. Nevertheless, it was no use railing against events. This was the course the world had taken, and she knew of no way to change things for the better.

That was her last call on this side of the Station. From here to the other side, she would have to go circuitously. Only cautious, fully-instructed working parties dared venture into the central area under the monster dome, because it was there that the-the trouble, the problem, the danger, whatever one chose to call it-the central mystery, perhaps, was located.

On her way past, Nestamay checked and stared at the enigmatic bulk of the inaccessible zone. It was changed, and yet unchanged. It had been part of her life since she was born, and still it retained its aura of alienness.

Twisted now and sagging, the arch of the dome spanned a good three miles of ground. Huge gashes, five or six times a man’s height, gave limited access to its interior. In the north was the least inhospitable section-some thousands of square yards were safe even for children, and it was there that the machinery on which the precarious life of the people depended was situated. There was food-ovens for bread, cauldrons for broth, vast hydroponic trays yielding fruit and vegetables from which spores of alien plants had to be scrupulously excluded. The north, too, was the side from which it was relatively safe to pillage scrap, to build or repair the miserable one-room shacks which served as their homes. Every now and again a working party managed to push back the limits of the safe area, either permanently-which was rare-or long enough at any rate to salvage some useful odds and ends.

Just what was hidden in the rank heart of the dome, no one could do more than guess.

Over the rusting structure creepers swarmed, bearing black sticky fruits that, if left to themselves, burst after a few months and sowed spores over everything-clinging spores, able to use anything organic as food. Nestamay had heard from Grandfather about unwary people who were struck by the spores in the old days, and who could not even be buried but had to be cremated with heatbeams lest another plant spring from the grave.

Pullulating fungi, a sickly orange in colour, grew on the branches of the creeper. Flowers, some of them of incredible beauty-and incredibly deadly, because the scent they gave off dulled the senses and laid one open to attack by swinging plant-tentacles-shone out here and there. Great toothed pseudo-leaves sprawled over the ground below, ready to close like a shroud on any trespasser …

Nestamay’s heart turned over, for at this very moment one of those pseudo-leaves opened in sight of her, with a grunting, scratching sound, exposing to view a disgustingly slimy object which at first she thought might be human remains.

A second look reassured her. It was only a thing which the plant had found indigestible after much trying. Now it was a shapeless jellied mass which the pseudo-leaf was attempting to displace over its edge, by humping up and forcing it to roll. The spectacle nauseated her. She went quickly on her way.

Every so often, the idea came from a hothead like jasper that what was needed was to march straight into the central area under the dome, heatbeams blazing, and clear out the entire fetid jungle. Every time, Grandfather or someone else vetoed the idea instantly.

In some incomprehensible way, their existence depended on leaving that central area alone-driving back the vegetation, killing any things that emerged from it, but otherwise enduring its hateful presence. Something was inside there, behind the sporulating fruits, the fungi and the pseudo-leaves, from which they derived their food, clothing, warmth and other basic necessities. Nestamay had pestered Grandfather over and over when she was a child with questions about this strange hidden master of their fate, and the answers had been confusing.