Both Mochi and Kotone froze completely at the sight before them.
Hanging above their heads was a gigantic heart, as large as an adult person. The mass of reddish flesh contracted and expanded slowly, covered by a network of dark veins that disappeared into the walls and ceiling.
THUMP.
THUMP.
Each heartbeat echoed throughout the place like the strike of a massive drum. The walls vibrated slightly with every pulse. The sound was so powerful that Mochi could feel it in her chest.
"Now it makes sense..." Kotone murmured.
Her voice was barely above a whisper, but Mochi's sharp ears caught it easily. She tore her gaze away from the monstrous organ and looked at her.
"What makes sense?"
Kotone did not answer immediately. Her eyes moved around the room as she analyzed everything they had seen so far.
"Everything."
"Everything?"
"The changes in the building's structure. The fact that we couldn't find an exit. That we were unable to locate the anomaly's exact position."
The young girl took a deep breath.
"Everything fits."
Mochi frowned.
"I don't understand."
"Because we've been analyzing the situation from the wrong perspective."
Kotone raised a hand and slowly gestured around them.
"We thought we had entered a barrier."
Mochi nodded. It was the most logical explanation.
"But we never entered a barrier."
"Then what...?"
Kotone looked up at the enormous heart beating above them.
"We're not inside a barrier... we're inside an anomaly."
Silence took over the room. Mochi felt her mind come to a halt for an instant.
"What?"
"The entire building is an anomaly."
"..."
Mochi blinked several times.
"The building... is an anomaly?"
"Yes."
"The whole building?"
"Yes."
"How the hell is that even possible?!"
Her voice echoed through the room.
"Did it swallow us? Are we in its stomach?"
"Obviously this isn't its stomach, idiot."
Kotone pointed upward.
"If its heart is right there."
Mochi looked up. The enormous organ continued to beat. For some reason, that logical observation made her feel even worse.
"If someone had told me something like this an hour ago, I would've laughed in their face."
Kotone was not exaggerating. There was a reason why she found it so hard to believe what she was seeing. Long before she officially became an agent, even before receiving her ether weapon, she had already spent years studying anomalies. It was an obsession that had begun during her childhood.
While other children dreamed of heroes and adventures, Kotone felt a fascination she could never quite explain for those supernatural creatures her family had spent generations fighting. She remembered the days of her childhood: the enormous family estates, the strict nannies, the bodyguards who constantly watched her every move—and how she always found ways to slip away from them.
She would often sneak into an old storage building located in one corner of the family gardens. She could still remember the massive wooden doors, heavy and ancient. Covered in the marks of time, they would reveal a true treasure once she managed to open them: old weapons, armor used by past generations, cursed objects sealed inside special containers.
Relics that would have thrilled any child.
But Kotone never paid attention to any of them.
Her goal was always the same: a huge bookshelf that occupied nearly an entire wall.
There, scrolls, journals, and documents accumulated over centuries were preserved. Accounts written by her ancestors, mission reports, research notes, records of defeated anomalies.
Day after day, while other children played, she sat reading those texts, filling her mind with knowledge about the enemy.
And that was precisely why the current situation was so disturbing.
Because among all those documents...
Among entire centuries of records...
She had never read anything like this.
Not a single reference.
Not a single mention.
Not a single description that matched what stood before them.
It did not fit into any known category.
It was something completely new.
And that was what truly frightened Kotone.
Was it an anomaly that had never been recorded?
A recent mutation?
Or was it a type of creature so dangerous that no one had survived long enough to document it?
Before her stood something that completely escaped everything she knew.
"What do we do? Normally I'd say we should attack the heart, but I think it's a weak point that's far too obvious. I mean, it's just hanging there without any kind of protection. Doesn't that seem suspicious? What if it's a trap? What do you think?"
"I don't know," Kotone replied without taking her eyes off the enormous organ. "Right now, I'm just as lost as you are."
Mochi blinked in surprise. She had expected an arrogant answer, some sarcastic remark, a comment criticizing her intelligence.
Anything but that.
Yet Kotone's response had been completely sincere.
"It might be a trap," the girl continued, "but we don't have many alternatives."
The heart continued beating above them.
THUMP.
THUMP.
The sound echoed throughout the entire chamber.
Kotone gripped the handle of her brush tightly. If that really was the anomaly's heart, they had to find out, and if it was a trap... they would discover it very soon.
The girl stepped forward, held the brush in front of her, and made a swift movement. For an instant, she looked more like a swordswoman than a sorceress. The tip of the brush left a dark trail in the air, and the next moment, a crescent of black ink shot forward.
The slash tore across the room at tremendous speed, heading straight for the heart.
Mochi held her breath, expecting to see the gigantic organ split in two, but that never happened. Halfway there, the blade of ink exploded violently. Ink was sent flying in every direction, some of it splattering against the walls, while more crashed into the nearby pillars.
The attack had been deflected or destroyed. For a second, neither of them understood what had happened. Then a figure slowly emerged from behind one of the enormous pillars supporting the ceiling.
The culprit was another anomaly.
Mochi felt a chill run down her spine. Neither of them had detected it. They had been so focused on observing the heart that they hadn't even noticed its presence, and that alone was terrifying enough. The new anomaly looked completely different from anything Mochi could have imagined.
It looked like a little girl, no more than eight years old. She wore an old black kimono covered in dirt and dark stains. Her long black hair fell down to her waist, and her bangs were so thick that they completely concealed her face. For a brief moment, observing her from a distance, she almost looked like an ordinary child. But it only took a closer look to understand that something was terribly wrong. Her skin was translucent. Not like human skin—it looked like wet paper. A thin, whitish layer beneath which dark veins could be seen spreading throughout her body. Her jaw hung unnaturally, as if it were partially dislocated, and her mouth... her mouth remained open, far too wide, much wider than any human being could manage.
The anomaly slowly turned her head toward them. The movement caused her bangs to shift slightly, and then they could see it—or rather... they could see the absence of it. Where her eyes should have been, there were only two deep black cavities, empty and dark, with no apparent bottom.
Mochi's heart skipped a beat. The instant that thing fully emerged, an icy chill ran down her spine. It wasn't discomfort or nervousness. It was fear. Her body was trying to tell her something, something very simple.
Run.
Mochi clenched her teeth and refused to listen to that impulse. Using all her willpower, she released a small pulse of ether. The energy expanded from her body, searching, analyzing, measuring... and when she received the response, she felt the blood run cold in her veins.
That anomaly was dangerous.
Terribly dangerous.
The energy emanating from it was dense and dark. Like an ocean of resentment compressed inside a child's body. Mochi had faced many anomalies since becoming an agent, but she had never felt anything like this. Only one creature had ever given her a similar sensation.
The gigantic ape anomaly Haruka had fought.
The creature tilted its head slightly, as if observing them.
Mochi swallowed. Beside her, Kotone did the same. The young genius didn't take her eyes off the anomaly.
"It's an A-rank..." Kotone whispered.
Even for her, those words were difficult to utter. The silence that followed was far more terrifying than any scream, because both of them understood perfectly what it meant.
An A-rank.
A threat completely beyond their reach.