“If you grow the pathogen in a dry, sterile medium,” she says, “it will eventually reveal its true nature. But its growth cycle is slow. Quite astonishingly slow. In the hungries themselves, it takes several years for the mycelial threads to appear on the surface of the skin–where they look like dark grey veins, or fine mottling. In agar, the process is slower still. This specimen is twelve years old, and it’s still immature. The sexual or germinating structures–sporangia or hymenia–have yet to form. That’s why it’s only possible to catch the infection from the bite of a hungry or direct exposure to its bodily fluids. After two decades, the pathogen still hasn’t spored. It can only bud asexually, in a nutrient solution. Ideally, human blood.”
“Why are you showing me this?” Justineau demands. “I’ve read the literature.”
“Yes, Helen,” Caldwell agrees. “But I wrote it. And I’m still writing it. Through the cultures I took from badly decayed hungries–cultures like this one–I was able to establish that the hungry pathogen is an old friend in a new suit. Ophiocordyceps unilateralis.
“We encountered it first as a parasite on ants. And its behaviour in that context made it notorious. Nature documentaries dwelled on every lurid detail.”
Caldwell proceeds to dwell on every lurid detail, but she really doesn’t need to. Back when she first identified the hungry pathogen as a mutant Cordyceps, she was so happy that she just had to share. She persuaded Beacon to approve an educational programme for all base personnel. They filed into the canteen in groups of twenty, and Caldwell started the show by playing a short extract from a David Attenborough documentary, dateline twenty years or so before Breakdown.
Attenborough’s perfectly pitched voice, honey from an English country garden, described with incongruous gentleness how Ophiocordyceps spores lie dormant on the forest floor in humid environments such as the South American rainforest. Foraging ants pick them up, without noticing, because the spores are sticky. They adhere to the underside of the ant’s thorax or abdomen. Once attached, they sprout mycelial threads which penetrate the ant’s body and attack its nervous system.
The fungus hot-wires the ant.
Images on the screen of ants convulsing, trying in vain to scrape the sticky spores off their body armour with quick, spasmodic sweeps of their legs. Doesn’t help. The spores have commenced digging in, and the ant’s nervous system is starting to flood with foreign chemicals–expert forgeries of its own neurotransmitters.
The fungus gets into the driving seat, puts its foot on the accelerator and drives the ant away. Makes it climb to the highest place it can reach–to a leaf fifty feet or more above the forest floor, where it digs in with its mandibles, locks itself immovably to the leaf’s spinal ridge.
The fungus spreads through the ant’s body and explodes out of its head–a phallic sporangium skull-fucking the dying insect from the inside. The sporangium sheds thousands of spores, and falling from that great height they spread for miles. Which of course is the point of the exercise.
Thousands of species of Cordyceps, each one a specialist, bonded uniquely with a particular species of ant.
But at some point a Cordyceps came along that was a lot less finicky. It jumped the species barrier, then the genus, family, order and class. It clawed its way to the top of the evolutionary tree, assuming for a moment that evolution is a tree and has a top. Of course, the fungus might have had a helping hand. It might have been grown in a lab, for any number of reasons; coaxed along with gene-splicing and injected RNA. Those were very big jumps.
“This,” Caldwell is saying, tapping the sealed lid of the fish tank, “is what’s inside the subjects’ heads. Inside their brains. When you walk into that classroom, you think you’re talking to children. But you’re not, Helen. You’re talking to the thing that killed the children.”
Justineau shakes her head. “I don’t believe that,” she says.
“I’m afraid it doesn’t matter what you believe.”
“They exhibit behavioural responses that have no bearing on the fungus’s survival.”
Caldwell shrugs off-handedly. “Yes, of course they do. For the moment. Waste not, want not. Ophiocordyceps doesn’t devour the entire nervous system all in one go. But if one of those things you think of as your pupils smells human flesh, human pheromones, it’s the fungus that you’ll be dealing with. The first thing it does is to consolidate its control of the motor cortex and the feeding reflex. That’s how it propagates itself–in saliva, mainly. The bite gives nourishment to the host and spreads the infection at the same time. Hence the extreme caution we take in the handling of the test subjects. And hence”–she sighed–“the need for this lecture.”
Justineau feels an intense desire to assert herself against a judgement that’s already been made. She takes hold of the lid of the fish tank and wrenches it open.
Caldwell gives a wordless yell as she recoils, hand clasped to her mouth.
Then she thinks about what she’s doing, and lowers her hand. She glares at Justineau, her cool detachment holed below the waterline.
“That was very stupid,” she says.
“But not dangerous,” Justineau points out. “You said it yourself, Caroline. No sex organs yet. No spores. No way for the fungus to spread in air. It needs blood and sweat and spit and tears. You see? You’re just as likely as anyone to make a false assessment–to see a risk where there really isn’t any.”
“It’s a poor analogy,” Caldwell says. There’s an edge in her voice you could part a hair on. “And overestimating risk isn’t even an issue here. The danger–all the danger–lies in ignoring it.”
“Caroline.” Justineau tries one last time. “I’m not arguing that we should stop the programme. Just that we should switch to other methods.”
Caldwell smiles, brittle, precise. “I’m open to other methods,” she tells Justineau. “That’s why I asked for a developmental psychologist to join the team in the first place.” The smile fades out, an inevitable ebb tide. “My team. Your methods are adjuncts to mine, called on when I need them. You don’t dictate our approach, and you don’t talk to Beacon over my head. Has it occurred to you, Helen, that we’re here under military rather than civilian jurisdiction? Do you ever think about that?”
“Not much,” Justineau admits.
“Well, you should. It makes a difference. If I do decide that you’re compromising my programme, and if I inform Sergeant Parks of that fact, you won’t be sent home.”