The Girl With All the Gifts(111)

“Put it in words you understand,” Melanie suggests, in much the same tone. “If it’s too hard for me, I’ll ask you to explain it again.”

So Caldwell delivers her lecture. Not to Elizabeth Blackburn, Günter Blobel or Carol Greider, but to a ten-year-old girl. That’s humbling, in a way. But only in a way. Caldwell is still the one who made all the connections and found what was there to be found. Who entered the jungle and brought the hungry pathogen back alive. Ophiocordyceps caldwellia. That’s what they’ll call it, now and for ever.

As the sky pales outside, she talks on and on. Melanie stops her every so often with pertinent and focused questions. She’s a receptive audience, despite her lack of a Nobel prize.

To the newly infected, Caldwell says, Ophiocordyceps is utterly without mercy. It batters down the door, breaks and enters, devours and controls. Then finally it turns what’s left of the host into a bag of fertiliser from which the fruiting body grows.

“But we were wrong about how quickly the human substrate is destroyed. The fungus targets different brain areas with differing speed and severity. It shuts down higher-order thought. It enhances hunger and the triggers for hunger. But we’d assumed that all drives outside of that–all behaviours that didn’t serve the parasite’s agenda–were embargoed at the same time.

“When I saw that woman in the street in Stevenage, and the man in the care home, I could see that wasn’t the case. Both of them were still making connections, haphazardly, to their former lives. They were engaging in behaviours–pushing a pram, singing, looking at old photographs–that were completely without function as far as the parasite was concerned.”

Caldwell looks up at Melanie. Her mouth is unpleasantly dry, despite the sweat that’s running freely down her face. “Can I have a glass of water?” she asks.

“When you’ve finished,” Melanie promises. “Not yet.”

Caldwell accepts the verdict. She reads nothing in Melanie’s face that would give her room for negotiation. “Well,” she says, her voice faltering a little, “that made me think. About you, and the other children. Perhaps we’d missed the obvious explanation for why you’re so different.”

“Go on,” Melanie says. Her voice is level, but her eyes betray her fear and excitement. It comforts Caldwell a little–in the absence of the physical control she used to enjoy–to have at least this degree of power over her.

“I realised that you might have been born with the infection. That your parents might already have been infected when you were conceived. We thought that was impossible–that hungries couldn’t have a sex drive. But once I’d seen the survival of other human drives and emotions–mother love, and loneliness–it didn’t seem impossible at all.

“With that in mind, I went back to the cytological evidence. I was fortunate enough to be able to obtain a fresh sample of brain tissue—”

“From a boy,” Melanie says. “You killed him and cut off his head.”

“Yes, I did. And his brain was very different from a normal hungry brain. With the equipment I had back at the base, it was pretty much all I could do to verify and map the presence of the fungus. With this…”–she indicates with a nod of the head the microtome, the centrifuge, the scanning electron microscope–“I could look at individual neurons and how the fungal cells interacted with them. The boy here, and the man from the care home, they were so different there was almost no way to compare them. The fungus utterly wrecks the brain of a first-generation hungry. Goes through it like a train. The chemicals it secretes–the brute-force triggers that turn specific behaviours on and off–they cause terrible damage as they accumulate. And the fungus is drawing nutrients from the brain tissue too. The brain is progressively hollowed out, sucked dry.

“In the second generation–that’s you–the fungus is spread evenly throughout the brain. It’s thoroughly interwoven with the dendrites of the host’s neurons. In some places it actually replaces them. But it doesn’t feed on the brain. It gets its nourishment only when the host eats. It’s become a true symbiote rather than a parasite.”

“Miss Justineau said my mother was dead,” Melanie objects. It’s almost a protest–as though a lie from Helen Justineau is a thing that can have no place in the world.

“That was our best guess,” Caldwell says. “That your parents were junkers or other survivors who’d never made it to Beacon, and that you and they had all been fed on and infected at the same time. We had no model for hungries copulating. Still less for them giving birth in the wild, and the babies somehow surviving. You must be much hardier and more self-sufficient than normal human infants. Perhaps you were able to feed on the flesh of your mother until you were strong enough to—”

“Don’t,” Melanie says sharply. “Don’t talk about things like that.”

But talking is all that Caldwell has left now, and she can’t stop herself. She talks about her observations, her theory, her success (in working out the pathogen’s life cycle) and her failure (there’s no immunity, no vaccine, no conceivable cure). She tells Melanie where to find her slides and the rest of her notes, and who to give them to when they get to Beacon.

When it becomes harder for Caldwell to talk, Melanie comes closer and sits at her feet. The scalpel is still clutched in her hand, but she doesn’t bully or threaten now. She just listens. And Caldwell is full of gratitude, because she knows what this lethargy that’s flooding through her means.