In the week following his capture, the world's first Chelation Disease patient died of massive internal bleeding in a local hospital. But by then, the disease had already begun to spread rapidly across the globe.
Chelation Disease was highly contagious, even in its earliest stages. Within about two hours of being infected by the pathogenic spores, the patient's bodily fluids became capable of infecting others.
The spores entered the body through mucous membranes, circulated through the bloodstream, and accumulated near the brain's capillaries. During this process, the most striking physiological change was a sharp drop in serotonin levels—explaining why the early symptoms so closely resembled depression.
Soon after, the fertilized cyst protozoa inside the spores matured, forming oocysts. The nuclei and cytoplasm within these oocysts repeatedly divided and multiplied, producing tens of thousands of offspring spores. When the oocysts finally ruptured, they flooded outward, physically breaching the blood-brain barrier and taking control of the host's neural activity.
The moment the blood-brain barrier was breached was the same moment the patient lost all rationality—completely enslaved by the Chelate Fungus. Even if they retained, for a brief while, the ability to interact socially or care for themselves, it was no longer accurate to call them "human."
Chelates were natural-born criminals. They took pleasure in killing—though it did little to spread the spores and often exposed them prematurely. Still, they did it with morbid delight.
Cynthia drove the car slowly through the winding roads around Severn Mountain, her voice calm as she narrated the grim history of Chelation Disease. Beneath the shade of a towering tree, she stopped the car, lit a cigarette by the window, and said softly, "But that's not the most terrifying thing about Chelation Disease."
Marcia looked at her, waiting for her to continue.
Cynthia went on, "Before symptoms appear, a patient with Chelation Disease won't sneeze, won't have a fever. Even if they feel exhausted or hollow inside, they can still act cheerful in front of others. There's only one way to confirm infection—by extracting cerebrospinal fluid.
"In other words, before proper diagnosis, there's no clear external sign to tell whether someone nearby is infected. That uncertainty... is what made the disease so terrifying."
"Why…?"
"Vigilantism," Cynthia said softly. "All around the world, self-proclaimed 'Chelate Hunters' began to appear. They would relentlessly track down anyone they suspected of being infected. Countless innocent people were killed because of it. Among the victims were not just misdiagnosed patients with depression, but also many quiet, introverted people who simply didn't know how to express themselves."
Cynthia exhaled a thin stream of smoke. "Those merely suspected were already treated this way—so imagine what life was like for those officially diagnosed. People's terror of Chelation Disease twisted into superstition. They believed only those who were filthy or morally corrupt could be infected. It was easier to think of the infected as inherently evil murderers chosen by demons, rather than accept that any of them could have been ordinary people.
"As a result, even those who were cured after treatment could never return to normal life again."
She paused, then added quietly, "That's why so many Chelation Disease patients, even when they felt their bodies changing, refused to seek medical help before it was too late. Since you grew up in a convent, I suppose you've heard such stigma more than once."
Marcia remembered Sister Gilding's gentle warnings and fell silent, unable to reply.
"In short," Cynthia continued, "many people went through unthinkable cruelty back then." She tapped her cigarette against the ashtray and gave a small, humorless smile. "Here's a grim little statistic—well, perhaps 'grim' is more accurate than 'interesting': about thirty-one percent of Chelation Disease patients, upon suspecting they might be infected, kept a sharp object on them at all times—a pair of scissors, a knife... even an axe. Do you know why?"
Marcia's body trembled slightly. "…Why?"
"Because they were terrified they really were infected—but too afraid to confirm it. So they carried those weapons intending to kill themselves if the worst came to pass." Cynthia's tone darkened. "But in the end, those same weapons often became the first tools they used to harm others once the disease took control."
The girl bit her lip hard.
"In any case," Cynthia said quietly, "to contain Chelation Disease, humanity paid an unimaginable price. And now, it's beginning to resurface in the wastelands. We're seeing signs of resurgence. We need allies—desperately." She turned her eyes to Marcia. "What do you think? Will you join us?"
Marcia couldn't speak. She simply gave a stiff, almost mechanical nod.
"Now I'll take you to the AHgA base in Tanyi City," Cynthia said. "You'll receive special training there — you'll learn how to identify Chelates and how to fight them.
I've also arranged psychological support for you through the Assistance Program. If there's anything you can't process, you can talk to a therapist. They'll evaluate your mental state and determine whether you're fit to begin combat training. …Did I make that clear?"
Marcia nodded. "Miss Cynthia, could you do me one more favor?"
"Hmm?"
"This scrapbook… could you please find a safe place to keep it for me?"
Cynthia glanced at the object in Marcia's hands. "No problem."
The two of them got back into the car.
Marcia stared blankly ahead, her eyes unfocused. She remembered the last time she saw Headmistress Elma. In the gentle smile on the old woman's face, Marcia had caught a faint trace of sorrow.
What kind of thoughts had filled Headmistress Elma's final month of life?
Was it confusion? Fear? Regret?
Or perhaps something else mixed in — emotions Marcia would never know. That kind and gentle headmistress, in the end, had become a silent accomplice of the darkness — trapped forever in the iron cage woven by her own hands and those of the people around her.
Marcia suddenly remembered the anthropologist's comment about the femur, and Sister Gilding's constant reminders about love and mutual aid — and that one line:
> "When we find ourselves in hardship, yet can still help one another, that is where our civilization begins."
Maybe she had never truly understood those words. She had never realized that asking for help, especially from those closest to you, could require such immense courage — that the nearer the person, the harder it became to speak.
Cynthia's cigarette had nearly burned out. She pressed the stub into the ashtray and asked, "Any other questions?"
Marcia shook her head.
"Alright then." Cynthia smiled faintly, her mood brightening as the car engine roared to life. "Let's go."
The back wheels of the old coupe kicked up clouds of yellow dust. On the empty mountain road, the two of them set off once more.
( End of Chapter )