Barriers Usually Break from Within
When the door opened, the cold corridor air brushed against my cheek.
The Imperial Princess took the lead. Two knights followed behind, with the young lady and me sandwiched between them as we headed toward the western gallery.
Nights in the Imperial Palace were ordinarily quiet, but tonight was different. Unresolved commotion still drifted in from somewhere distant before fading away again. Only the barrier lamps set along the corridor walls burned at regular intervals — and here and there, one or two of those lights were missing. Moments ago, the line of light had been stable and unbroken.
When I drew a breath, the faint mingled scents of iron and scorched stone came with it. The smell of overheated barrier stones cooling down.
Without slowing her pace, the Princess asked,
"The bypass line you secured earlier — is it still holding?"
"It should be holding without issue."
"…Then the problem lies somewhere else."
"That's the more likely possibility, yes."
At my less-than-certain answer, the young lady added quietly from beside me,
"If the western auxiliary axis has been damaged, the palace's entire barrier network is probably drawing power from other lines to patch the gap for now."
The Princess glanced at her.
"Does the young lady of Rubenheim know barrier theory as well?"
"I know as much as is required to maintain a duchy's defensive lines."
It was a brief exchange, free of any excess on either side. Listening to them was somehow exhausting in itself.
At the end of the corridor, a guard knight was waiting. The moment he saw us, he bowed deeply — the courtesy directed not at me or the young lady, but at the Princess.
"Your Highness. The seals around the barrier chamber have been reorganized. However, the interior is still…"
The knight trailed off, flicking a glance in my direction. The Princess spoke without concern.
"There's no need to worry. From this point on, these two will move only under my orders. Isn't that right?"
These two. Being bundled together like a pair of objects wasn't particularly pleasant, but at least it meant we weren't being treated as obstacles.
We stopped before the western auxiliary barrier chamber. The door stood half open. A sealing cord stamped with the imperial crest lay cut and fallen on the floor, a thin scatter of something like black ash around it.
I paused at the threshold.
"…There's one thing I should say before we go in."
The Princess turned.
"Go on."
"You said the administrator inside was found collapsed."
"That's correct."
"That man didn't collapse from a barrier backlash."
The knight's face hardened.
"On what grounds do you—"
"If a barrier had backlashed, there would be more residual traces outside the door. Look." I pointed to the thin ash scattered before the entrance. "It's too shallow. If a barrier had ruptured from inside, the ash would have sprayed in every direction. This looks more like residue that seeped out through a gap that had already been opened."
The Princess was silent for a moment, then raised a hand. The knight's protest died there.
"Record that for now."
"Yes, Your Highness."
Stepping through the door, the air was different — the cool emptiness of a hollowed-out space. At the center of the room stood a circular barrier platform, three blue crystal axes floating above it. Complex mana patterns spread across the floor below like a spider's web. And in the middle of it all, a person lay collapsed.
A middle-aged man who appeared to be an imperial barrier administrator. The chest of his uniform was torn, and dark red scratch marks remained along the side of his neck.
The Princess spoke first.
"Is the administrator alive?"
The healer standing watch bowed hastily.
"He has a pulse, but… he has yet to regain consciousness."
I looked at the floor before I looked at the fallen man. One line of the pattern beneath the barrier platform was smoothly empty — more accurately, it had been deliberately torn out. Someone had selected only what they needed and ripped it free.
The young lady seemed to have noticed the same thing.
"This is strange."
The Princess lowered her gaze.
"In what way?"
"If the intent had been destruction, the damage should have been larger and rougher. This is far too precise."
I continued where she left off.
"Traces like these are usually left when something is being opened."
No one spoke immediately. The Princess repeated the word slowly.
"…Opened?"
"Yes. This intruder wasn't trying to destroy the barrier chamber. They were trying to leave a specific axis vacant — even if only for a very short time."
I approached the edge of the circular platform and knelt. Up close, it was even clearer. Using a deconstruction tool left that kind of grain — though this was far more refined than anything an ordinary administrator would produce.
"This isn't the work of someone who hastily imitated the technique."
The Princess asked,
"…Meaning?"
"Either a skilled practitioner who already knew how to handle barriers did this, or at the very least, someone who had watched one work for a long time."
One of the knights by the door swallowed a low curse. The implication was clear enough: the culprit was likely someone from the inside.
Without a word, the Princess moved to the fallen administrator's side. After looking down at his face for a moment, she asked the healer,
"Aside from the external injuries, was there anything else unusual?"
The healer hesitated before answering.
"There are burns on his fingertips. Similar to the wounds that form when a deconstruction tool is gripped too hard, but… I can't be certain."
I looked down at the administrator's right hand. Thin scorch marks remained across two finger joints — but the palm bore none of the pressure calluses typical of someone who had held a tool for any length of time.
"These aren't his hands."
The healer and the knight both looked at me. I pointed to the fingertips.
"The traces are far too shallow. Just a brief contact. It's more likely someone pressed the tool into his hand, or that it touched him after he was already down."
The Princess said quietly,
"So they meant to frame him."
"…Given the circumstances, that conclusion seems reasonable."
The young lady had gone around to the far side of the platform and picked up a metal fragment from the edge of the floor — a shard no larger than a fingernail.
"Your Highness."
The Princess looked up.
"It's a piece of the auxiliary lock. Torn free from the inside."
"So they didn't come in from outside…?"
"No. Someone who was already inside unlocked it themselves and did the work."
The Princess's expression grew colder still.
I examined the center of the barrier platform again. The light of one blue crystal axis was trembling — ever so slightly. To anyone else it would have looked intact, but an axis that had been improperly opened once left traces even after it was fully closed. At the end of that tremor, an unfamiliar sensation caught.
An extremely thin grain. It resembled the black residue I'd felt in the banquet hall earlier, but this was more refined, deeper. It felt like someone had deliberately left a path open.
I reached out without thinking.
"Don't touch that."
The Princess's voice cut sharply through the air. My fingertips stopped in empty space.
"It's dangerous. There's no telling what might happen."
Without withdrawing my hand, I said,
"Even so, it needs to be checked."
Our eyes met. After a brief silence, she spoke.
"Sir Elberhart. Promise me one thing."
"…What is it?"
"The moment it feels even slightly dangerous, pull your hand away at once. That is an order."
Only then did I bring my fingertips close to the crystal axis. The instant they made contact, a hollow sensation with no warmth at all seeped into my skin. The interior of the barrier rang lightly, like tapping an empty bell.
It was vacant.
I narrowed my eyes.
"…Your Highness."
"Don't hesitate. Speak."
"This wasn't opened once and then finished."
The young lady asked immediately,
"What does that mean?"
"Someone was testing it. They created a gap for a very short time and watched to see what would come through — and how much."
Silence settled over the room. The Princess repeated the word slowly.
"A test… you say?"
"Yes. Tonight's disturbance was closer to reconnaissance than destruction. They wanted to see how far they could open it, and what would respond to that gap."
"…And what were they trying to confirm?"
Instead of answering, I looked at the trembling axis. Someone could reach the barriers deep inside the Imperial Palace. And that someone also knew that the black things outside could sense this opening.
There was no good news in any of it.
"From inside the palace," my voice dropped lower, "they wanted to see how far they could open it."
In that moment, a short vibration rang out from beneath the barrier platform.
Tak.
It was a small sound, yet a chill ran straight up my spine. I raised my head.
"Step back."
The Princess moved at once. The young lady retreated a pace as well, gathering blue-white mana at her fingertips. The knights drew their swords and formed a ring around the platform.
One of the blue crystal axes tilted slowly. The healer caught her breath.
"Surely it isn't still—"
Before the words could finish, a single black fissure stretched long from a gap in the pattern beneath the platform.
I clenched my teeth.
"It's still inside."
Golden mana flared across the back of the Princess's hand.
"…What is it?"
Looking past the trembling axis at the darkness just beginning to open, I answered.
"Something worse than whatever came through the first time."