The path chosen by Alexius offered no immediate resistance.
And that alone was suspicious.
The tunnel descended at a gentle incline, wide enough for them to walk side by side. The walls were unlike the previous ones — not merely raw stone, but surfaces worn smooth by time, carved with deep inscriptions.
They were not words.
They were records.
Carved figures depicted ancient beings — some humanoid, others distorted, others nearly unrecognizable. There were scenes of battle. There were seals being raised. There was a mountain drawn again and again.
And in more than one of them, a triangular symbol.
Ichika was the first to notice.
— Sensei… — she murmured. — This here…
Alexius had already seen it.
But he did not answer.
The next carvings showed something more unsettling: figures kneeling before an immense door. In their hands, they held triangular objects that glowed.
— This isn't decoration — Shirō said quietly. — It's instruction.
The corridor ended.
And the chamber opened before them.
Gigantic.
The ceiling vanished into upper darkness, supported by massive columns that resembled inverted roots. The air was heavy, yet stable. At the far end of the chamber, occupying nearly the entire wall, stood the door.
Colossal.
Forged from dark stone, smooth, marked by lines converging toward a single central point.
A recess.
Triangular.
No one needed to say anything.
All eyes turned to Alexius.
He remained still for a few seconds.
Then he slipped a hand inside his cloak.
The students watched — too attentively.
And then they saw it.
He withdrew the artifact.
A triangle of unknown metal, the size of an open hand. Its edges were too precise to have been shaped by ordinary tools. At its center, a soft blue light pulsed — not intense, but alive.
Ichika's eyes widened.
— You had that the whole time?
Yumiko frowned.
— That… is that the sealed artifact?
Kensha stepped forward.
— So that's why you didn't want us touching it.
Alexius did not deny it.
The triangle began to vibrate.
Not violently — but as if it had recognized something. The blue light intensified slightly, pulsing at quicker intervals.
The chamber responded.
Almost imperceptibly.
— I suspected — Alexius said at last. — But I wasn't certain.
He walked toward the door.
The closer he came, the stronger the artifact pulsed. The blue light now traced subtle lines through the air, nearly invisible, linking it to the recess in the colossal structure.
Ichika felt a chill run down her spine.
— It's calling.
Alexius raised the triangle.
The recess seemed crafted precisely for it.
He did not hesitate.
He inserted it.
The contact was smooth.
Silent.
For one second… nothing happened.
Then the triangle glowed.
Not like an explosion.
Like a breath.
A blue pulse expanded from the junction between artifact and door, spreading across the stone surface in fine lines, filling the ancient engravings as though rekindling something long dormant.
The ground trembled faintly.
The columns seemed to adjust.
The air thickened — only for an instant.
Alexius felt it.
It was not force.
It was activation.
Something had been recognized.
Something had been awakened.
The pulse faded.
And the triangle… disappeared.
It did not fall.
It did not crack.
It did not burn.
It simply ceased to be there.
The students fell into absolute silence.
Ichika spoke first.
— Sensei… it—
— I know — Alexius replied, still staring at the now-empty recess.
The door began to move.
Slowly.
Stone grinding against stone.
A deep sound echoed through the chamber, like a mechanism that had not been engaged for centuries. A vertical line split open at the center, revealing darkness beyond.
No wind escaped.
No creature emerged.
But something within… was waiting.
Shirō swallowed.
— The artifact… was it disposable?
Alexius remained silent for one second longer.
— No — he answered at last. — Nothing here was disposable.
The door continued to open.
And somewhere distant within Monte Arf — so distant it could not be measured in steps — a similar vibration traveled through another dormant structure.
Small.
Subtle.
But present.
The activation was not complete.
Not yet.
Alexius took the first step toward the opening.
— We continue.
And Monte Arf, once again, did not stop them.
Because something very old had been set back into motion.
And now… the path could no longer be closed in the same way.