Alastair Reynolds: Beyond the Aquila Rift: The Best of Alastair Reynolds

She was inhumanly beautiful.

“You said things were much worse,” Clavain said. “Are you ready to show me now?”

SHE TOOK HIM to see Felka again, passing on the way through deserted nursery rooms, populated now only by bewildered mechanical animals. Felka was the only child left in the nursery.

Clavain had been deeply disturbed by Felka when he had seen her before, but not for any reason he could easily express. Something about the purposefulness of what she did; performed with ferocious concentration, as if the fate of creation hung on the outcome of her game. Felka and her surroundings had not changed at all since his visit. The room was still austere to the point of oppressiveness. Felka looked the same. In every respect it was as if only an instant had passed since their meeting; as if the onset of war and the assaults against the nest—the battle of which this was only an interlude—were only figments from someone else’s troubling dream; nothing that need concern Felka in her devotion to the task at hand.

And what the task was awed Clavain.

Before he had watched her make strange gestures in front of her. Now the machines in his head revealed the purpose that those gestures served. Around Felka—cordoning her like a barricade—was a ghostly representation of the Great Wall.

She was doing something to it.

It was not a scale representation, Clavain knew. The Wall looked much higher here in relation to its diameter. And the surface was not the nearly-invisible membrane of the real thing, but something like etched glass. The etchwork was a filigree of lines and junctions, descending down to smaller and smaller scales in fractal steps, until the blur of detail was too fine for his eyes to discriminate. It was shifting and altering colour, and Felka was responding to these alterations with what he now saw was frightening efficiency. It was as if the colour changes warned of some malignancy in part of the Wall, and by touching it—expressing some tactile code—Felka was able to restructure the etchwork to block and neutralise the malignancy before it spread.

“I don’t understand,” Clavain said. “I thought we destroyed the Wall; completely killed its systems.”

“No,” Galiana said. “You only ever injured it. Stopped it from growing, and from managing its own repair-processes correctly…but you never truly killed it.”

Sandra Voi had guessed, Clavain realised. She had wondered how the Wall had survived this long.

Galiana told him the rest—how they had managed to establish control pathways to the Wall from the nest, fifteen years earlier—optical cables sunk deep below the worm zone. “We stabilised the Wall’s degradation with software running on dumb machines,” she said. “But when Felka was born we found that she managed the task just as efficiently as the computers; in some ways better than they ever did. In fact, she seemed to thrive on it. It was as if in the Wall she found…” Galiana trailed off. “I was going to say a friend.”

“Why don’t you?”

“Because the Wall’s just a machine. Which means if Felka recognised kinship…what would that make her?”

“Someone lonely, that’s all.” Clavain watched the girl’s motions. “She seems faster than before. Is that possible?”

“I told you things were worse than before. She’s having to work harder to hold the Wall together.”

“Warren must have attacked it.” Clavain said. “The possibility of knocking down the Wall always figured in our contingency plans for another war. I just never thought it would happen so soon.” Then he looked at Felka. Maybe it was imagination but she seemed to be working even faster than when he had entered the room; not just since his last visit. “How long do you think she can keep it together?”

“Not much longer,” Galiana said. “As a matter of fact I think she’s already failing.”

It was true. Now that he looked closely at the ghost Wall he saw that the upper edge was not the mathematically smooth ring it should have been; that there were scores of tiny ragged bites eating down from the top. Felka’s activities were increasingly directed to these opening cracks in the structure; instructing the crippled structure to divert energy and raw materials to these critical failure points. Clavain knew that the distant processes Felka directed were awesome. Within the Wall lay a lymphatic system whose peristaltic feed-pipes ranged in size from meters across to the submicroscopic; flowing with myriad tiny repair machines. Felka chose where to send those machines; her hand gestures establishing pathways between damage points and the factories sunk into the Wall’s ramparts which made the required types of machine. For more than a decade, Galiana said, Felka had kept the Wall from crumbling—but for most of that time her adversary had been only natural decay and accidental damage. It was a different game now that the Wall had been attacked again. It was not one she could ever win.

Felka’s movements were swifter; less fluid. Her face remained impassive, but in the quickening way that her eyes darted from point to point it was possible to read the first hints of panic. No surprise, either: the deepest cracks in the structure now reached a quarter of the way to the surface, and they were too wide to be repaired. The Wall was unzipping along those flaws. Cubic kilometres of atmosphere would be howling out through the openings. The loss of pressure would be immeasurably slow at first, for near the top the trapped cylinder of atmosphere was only fractionally thicker than the rest of the Martian atmosphere. But only at first…

“We have to get deeper,” Clavain said. “Once the Wall goes, we won’t have a chance in hell if we’re anywhere near the surface. It’ll be like the worst tornado in history.”

“What will your brother do? Will he nuke us?”

“No; I don’t think so. He’ll want to get hold of any technologies you’ve hidden away. He’ll wait until the dust storms have died down, then he’ll raid the nest with a hundred times as many troops as you’ve seen so far. You won’t be able to resist, Galiana. If you’re lucky you may just survive long enough to be taken prisoner.”

“There won’t be any prisoners,” Galiana said.

“You’re planning to die fighting?”

“No. And mass suicide doesn’t figure in our plans either. Neither will be necessary. By the time your brother reaches here, there won’t be anyone left in the nest.”

Clavain thought of the worms encircling the area; how small were the chances of reaching any kind of safety if it involved getting past them. “Secret tunnels under the worm zone, is that it? I hope you’re serious.”

“I’m deadly serious,” Galiana said. “And yes, there is a secret tunnel. The other children have already gone through it now. But it doesn’t lead under the worm zone.”

“Where, then?”

“Somewhere a lot further away.”

WHEN THEY PASSED through the medical centre again it was empty, save for a few swan-necked robots patiently waiting for further casualties. They had left Felka behind tending the Wall, her hands a manic blur as she tried to slow the rate of collapse. Clavain had tried to make her come with them, but Galiana had told him he was wasting his time: that she would sooner die than be parted from the Wall.

“You don’t understand,” Galiana said. “You’re placing too much humanity behind her eyes. Keeping the Wall alive is the single most important fact of her universe—more important than love, pain, death—anything you or I would consider definitively human.”

“Then what happens to her when the Wall dies?”

“Her life ends,” Galiana said.

Reluctantly he had left without her, the taste of shame in his mouth. Rationally it made sense: without Felka’s help the Wall would collapse much sooner and there was a good chance all their lives would end; not just that of the haunted girl. How deep would they have to go before they were safe from the suction of the escaping atmosphere? Would any part of the nest be safe?