Chapter 4: Ninth Fortress

An He felt unusually exhausted.

Heidi took the unconscious Asta from her arms and laid her on the back seat, wrapping the wounds with practiced ease using strips of old cloth. “What happened?” Heidi asked, her face etched with disbelief as she pressed An He for details on the recent events.

“I don’t… know.” An He rubbed her forehead, only noticing the sticky sensation when she felt it—her hand was covered in blood. She couldn’t tell if it was hers or Asta’s.

It was as if she’d briefly lost her memory.

Upon closer reflection, it wasn’t quite amnesia. It felt more like her soul had been shoved aside, some unknown entity taking control of her body. She’d watched like a detached observer as a dense flock of birds erupted from her, as she leaped from the vehicle and raced toward Asta at an impossible speed.

And then…

Her memories grew chaotic after that, until the sound of Heidi’s tires jolted her awake. Only then did she regain her senses, finding Asta slumped over her shoulder.

An He dropped her hand and shrugged. “I must’ve had another episode. You know, the mental illness I mentioned.”

It wasn’t the first time this had happened. In the psych ward, the doctors had called it “dissociation.”

Was it dissociation? It didn’t quite feel the same. After all, she hadn’t endured any unbearable trauma this time.

“You’re actually sick? I thought you were joking.” Heidi took a deep breath. “Those Ravens—they’re connected to you?”

“Probably?” An He tilted her head.

Heidi’s expression turned peculiar. She seemed on the verge of saying something but held back, instead shoving An He toward the vehicle. “Let’s go, let’s go—back to base first. You’re too weird. I need to hand you over to the organization.”

An He vaguely sensed that Heidi’s urgency stemmed from a fear she might bolt.

The vehicle roared back onto the road leading to the fortress.

An He settled into the back seat, with Asta’s head pillowed on her lap.

Despite her best efforts to avoid looking at Asta’s body, the metallic tang of blood filling her nostrils dragged her thoughts back to the wounds—Asta had severed her own right arm and had her leg blown off. In exchange, she’d utterly obliterated one Bone Eater.

And those scattered bones had been carried off by the others.

“Can she still live?” An He’s voice trembled with tension.

Heidi floored the accelerator. “Hard to say. The Ninth Fortress’s medical tech isn’t top-tier.”

There was little emotion in Heidi’s tone. She even mused aloud, a smirk tugging at her lips. “If she doesn’t make it, we’ll give her a proper funeral. You ever hear about how elephants mourn their dead? Like that—we’ll gather around Asta’s body, pay our respects, gently touch her forehead, palms, and ankles. The spots we interacted with most. A tribute.”

“For a warrior like Asta, we’ll build her a monument too. Her name carved into the stone, living on forever with it.” Heidi snapped her fingers, as if already at the ceremony. “Pretty cool, right?”

“You’re hoping she dies?”

“Nah.” Heidi let out a hearty laugh. “But death’s just part of life for us.”

An He pursed her lips. Heidi’s reaction proved the point perfectly—because it was so commonplace, they could accept it with calm detachment. An He had already witnessed how Thorn Lamp’s view on life and death defied common sense.

“Still, I hope she pulls through,” Heidi added. “I’ve partnered with Asta since I was fifteen. Honestly, I can’t stand her sometimes—she’s so rigid, all principles and no flexibility. We argue every trip out.”

Heidi paused. “But I respect her too. Don’t let that gun-to-your-head moment fool you—she’s saved a ton of people. Including you, that’s gotta be at least thirteen. With folks like her around, the fortress gets better.”

Heidi started humming a tune as she sped along, the sand and gravel kicked up by the tires clattering against the spiked rims.

She fished a rectangular piece of metal from the pocket of her overalls and tossed it back to An He.

An He wiped the blood from her palm with her shirt and caught it. It was a weathered harmonica.

The metal on both sides gleamed smoothly, clearly polished often—spotless amid the vehicle’s junkyard clutter. “What’s this?”

“Asta’s harmonica. She hands it to me for safekeeping on every outing, and I give it back when we return.” Heidi glanced at the unconscious Asta. “Back at the fortress, she plays old melodies on it. Honestly, sounds awful.”

“The one you were just humming?”

“Yeah.”

“Yours sounds awful too.”

An He wanted to even the score for Asta—Heidi was clearly trash-talking while she was out cold. Their relationship must really be rocky.

Still, An He hadn’t expected the stern, rugged Asta to have such a hobby.

“Hmph.” Heidi huffed in annoyance. “I was just humming randomly. Art doesn’t mean much out here. Survival’s what everyone cares about.”

She fell silent, but moments later, she started humming the tune again. “Weird, this melody’s stuck in my head now.”

An He listened closely. It was an unfamiliar melody—melancholy and winding, full of trills. Back home, it reminded her of folk tunes from the northern continents: bold one moment, profound the next.

But Heidi’s version sounded like she was having a seizure.

Amid the melody, An He spotted a misty silhouette in the distance—a towering city wall piercing the clouds. This man-made behemoth rose from the earth, barricading the Wasteland. Too far to make out its construction, but the dim sunlight traced gleaming arcs across its surface, smooth and austere. Not brick or concrete.

That had to be the Ninth Fortress.

An He carefully shifted her numb leg. “Heidi, what’s a Nestsoul?”

“Nestsoul, huh? I figured you knew since you didn’t ask sooner.” Heidi blinked in mild surprise but explained patiently anyway.

“A Nestsoul is our mental energy made manifest. It can be summoned, seen, and aids in combat. Folks like us who awaken them are called Embedded Spirit Bodies. Seen my Little Squirrel? Cute, right?”

“Cute.” An He felt like Heidi was showing off. “Does everyone awaken one?”

“Of course not. They’re super rare—one in every twenty or thirty thousand.”

“Then why do some become Embedded Spirit Bodies?” An He glanced down at her own wounds.

The way those Ravens had appeared matched Heidi’s Nestsoul perfectly. If they were hers, she could only link it to those earlier scratches.

Did disaster turn into fortune for me?

No way—that’s protagonist treatment in some novel.

Good luck like that wouldn’t land on me.

But Heidi’s answer was unexpected. “Our abilities come from our mothers.”

“Hm?” An He snapped out of her thoughts, curiosity piqued.

Heidi eyed the timing for fortress entry before speaking slowly. “It took us a long time to figure out the origin of Embedded Spirit Bodies—mothers infected with Bone Erosion Disease who healed during the latent phase give birth to or raise girls who have a small chance of awakening Nestsouls. These mothers are low-level fungal carriers, but miraculously, their kids are fully immune to Bone Erosion Disease. Even injuries don’t cause mutation.”

Heidi described it poetically. “It’s like the Mother Body becomes a barrier, intercepting the disease and evolving a special ability as a gift for the child.”

“But that doesn’t work in reverse—not every infected mother produces an Embedded Spirit Body. The odds are still tiny; we haven’t cracked the rule yet.”

It sounded like a glitch left by Bone Erosion Disease. As it eroded humanity, human bodies fought back, evolving some extreme countermeasure. Like plants developing toxins after years of pest harassment.

Life on this planet was a delicate balance of give and take, wondrous in its way.

Heidi glanced back. “You think that’s a good thing?”

An He whispered, “Isn’t it? Immunity to Bone Erosion Disease sounds lucky.”

“Unfortunately, Embedded Spirit Bodies don’t live long. We grow faster, bigger than other kids, but our average lifespan is only forty. Factor in combat losses, and it’s down to thirty for a long life. Most awaken around fifteen; I’ve only had mine for five years.”

Heidi continued, “So no one sees it as a blessing. Too risky—no one casually tries breeding Embedded Spirit Bodies.”

“But.” Heidi’s tone brightened. “Asta’s thirty-one already. Maybe she’ll shatter those lifespan limits someday.”

She always sounded so upbeat, full of hope.

An He eyed her wound again. Then why did I awaken one?

My mom could never have had Bone Erosion Disease.

She pictured her mother first—those stern, downturned lips.

Unaware of An He’s shift in mood, Heidi kept explaining. “Naturally, Embedded Spirit Bodies are built for battle, so nearly all of us join Thorn Lamp. Besides Nestsouls, we awaken one Innate Talent each—like super vision or brute strength. One Talent and one Nestsoul per lifetime.”

“All animals?”

“Yeah. We figure humanity’s primal mental form is beastly, so Nestsouls are mostly animals, tied closely to the host.”

Heidi added, “Personality, character, hobbies—they all shape the Nestsoul at awakening. When I first met my Little Squirrel, I was bummed for days. Not exactly combat material.”

She adjusted her goggles with one hand. “Your Ravens… hmm, didn’t peg you for someone so dark.”

“I’m not. I swear.” An He denied it. She wasn’t dark.

If anything, it matched the half-dead aura clinging to her.

Or so she guessed.

The High Wall loomed closer now. An He could see it was forged from steel—gleaming smooth, impossible for Bone Eaters to climb. Every so often, protruding defensive bastions dotted it, manned by patrolling figures.

It was magnificent, reassuring. An He couldn’t help thinking of Heidi’s phrase—the Mother Body’s Barrier.

The wall guards spotted Heidi’s vehicle and opened the gates. The battered off-roader finally carried them into safety.

“Last thing,” Heidi said as she entered the wide, clean road, waiting for the entrance gates to seal shut. “Everyone’s Nestsoul is a single entity—even for birds. So, An He, you’re weird all around. If you were just a normal survivor, I’d drop you at the residential hospital…”

She turned, pulling down her dust mask, still grinning innocently. “But now? Sorry, straight to Thorn Lamp’s Research Lab to assess your threat level. Forgive the liberty with your freedom.”

Those pitch-black eyes were clear and pure, but An He saw through it—Heidi wasn’t as guileless as she seemed.

These people are no pushovers.

An inexplicable tension and sense of crisis welled up in An He. She instinctively tensed her muscles.

Who was she? How had she gotten here? Was she a threat? Even she didn’t know. Who knew what horrifying data they’d uncover, or what “specimen” label they’d slap on her.

Careless, careless, so careless.

She was really getting handed over to an unknown organization.