Chapter 126 | After Rebirth, I Became the Dungeon's Hidden Boss

Isolde pulled out the 《Celantia Trade Route Atlas》 from the side, preparing to continue examining the route to Red Kite, when an old book pressed at the very bottom suddenly slid out.

Its spine hit the corner of the desk with a dull thud.

Isolde looked down. It was a black hardcover book with no title.

The cover was cracked, and the edges still bore the faint char marks of fire.

She picked up the book and flipped it open, only to realize that this was not a history book written during any single era.

It was more like a record of disasters, continuously updated by successive owners.

The first half recorded the chaotic wars that had raged across the continent hundreds of years ago.

Back then, various kingdoms, churches, and races fought one another for land, resources, and divine authority. Many faiths that had now vanished once boasted vast numbers of followers.

She flipped through it quickly. The further back she went, the newer the handwriting and paper became, and the recorded events gradually approached the present.

One page detailed a border disaster that had occurred forty years ago.

【In the year 281 of the Royal Calendar, an undead lord led a legion of the dead across the northwestern defensive line. Black roots erupted from the ground in their wake, and three border cities fell in quick succession.】

【The dead in the cities rose once more, and dark red patterns surfaced beneath the skin of the survivors. Ordinary purification spells could not stop the corruption from spreading further.】

【Augustine Stuart, only eighteen at the time, personally led the royal knights to the border. He slew the undead lord outside Salt Marsh City, then purified the three cities with Holy Radiance, completely incinerating the decayed roots entrenched underground. A year later, he was elected by the Holy Court as the twelfth Hero King.】

【Taking forty-seven days in total, the three border cities were reclaimed under the Holy White Capital.】

Judging from the records, this war was categorized as an undead calamity.

Augustine's feats of slaying the undead lord and reclaiming the three cities became one of his most crucial achievements after being chosen by the Holy Court to ascend the throne.

It seemed the royal family was not hereditary, but rather elected by the Holy Court based on their contributions.

This not only gave every knight a seemingly equal chance to become a Hero King, but it also made them willingly shed their blood in loyal service to the Holy Court.

Moreover, with the "Hero King" serving as a living advertisement, believers flocked to the cause even more eagerly.

No wonder they went to such great lengths to manufacture holy lanterns; fresh hearts were always in ample supply.

Isolde continued reading. The subsequent records were highly chaotic.

Some believed it was a plague, while others claimed it was a punishment handed down by some evil god.

There were also those who believed that the unrotted corpse of some god was buried deep underground.

In the end, the person responsible for recording the disaster failed to find an answer.

Looking at the words “black roots,” the image of the Decayed Residual Root flashed across Isolde's mind once more.

She kept flipping forward. Many pages were missing, leaving only a few blurry, hand-drawn illustrations.

Entangled roots, an unidentified black substance, and an eye hidden within a dark red fissure.

Beside the drawings, several lines of text were written in a hand different from the original text.

The handwriting was messy, and the ink was noticeably newer. Isolde recognized it at a glance.

It was Valen's handwriting.

【This is not a plague.】

【Plagues only spread; they do not choose.】

【This power has a clear preference. It actively seeks out a container capable of bearing it.】

The next line had been repeatedly scribbled out.

Isolde held the page closer to the candlelight, barely managing to decipher the crossed-out words.

【They lied. Holy Radiance cannot truly destroy Decay.】

【They are more like two forces that repel yet attract each other.】

Further down, only the final two sentences remained.

【The roots are merely its hands reaching out to the outside world.】

【The real entity has perhaps never left its seal.】

Isolde's gaze gradually darkened.

If Valen's judgment was correct, then what Augustine had purified forty years ago was merely the three cities.

The true source of Decay might have never been destroyed.

Valen had not merely been contaminated by the power of Decay; he had once actively researched it.

And judging by the contents of the notes, his understanding of Decay clearly far surpassed that of an ordinary victim.

Isolde continued searching and found a single, cut-out slip of paper tucked behind the pages.

There wasn't much written on it, resembling a hasty record Valen had left after some observation.

【Upon contact with holy mana, the sample's activity decreases.】

【Upon contact with Malice mana, significant proliferation occurs.】

【No, I need more. As long as I do as she says, I can...】

The writing cut off abruptly there.

The lower half of the paper had been cleanly sliced away by a sharp tool, leaving only a smooth edge.

“She?”

Who was the “she” Valen spoke of?

The first two sentences were normal experimental records.

But by the final sentence, the handwriting had grown visibly frantic, even leaving several shallow tears in the paper.

Was what Valen wanted more samples of Decay, or more of this power itself?

That line, “as long as I do as she says,” at least proved that Valen had once communicated with some entity behind the Decay.

The other party had demanded he complete certain tasks, promising him a reward substantial enough to make him lose his sanity.

Isolde recalled Valen's dying screams. Up until his final moments, he still firmly believed he was a Demigod Candidate.

The thing promised to him by that entity was, in all likelihood, a Divine Seat.

It seemed the entity Valen had established contact with possessed a formidable background. Otherwise, he wouldn't have willingly turned himself into such a monstrous state.

Isolde looked back at the experimental records from earlier.

Holiness was capable of reducing the sample's activity.

Coincidentally, she possessed the power of holiness within her body, and since the Decayed Residual Root had entered her, it had not yet triggered any out-of-control contamination like that of the treants.

Perhaps there was a connection between the two.

But relying solely on the few lines left by Valen was not enough to prove that holiness was actively suppressing the root.

It could also be that the root had not truly awakened yet, or perhaps this body was inherently capable of enduring Decay.

Before figuring this out, she could not rashly absorb any more Holiness Fragments.

Especially since Valen had also written that an abnormal attraction would occur when the two powers came into contact.

Whether strengthening her holiness would suppress the Decay or stimulate it into further activity was something no one could be certain of right now.

The safest approach was to use her existing power of holiness to conduct small-scale probes, observe the root's reaction, and then decide whether to strengthen the suppression or find a way to extract it.

After all, no one wanted to keep a ticking time bomb that could detonate at any moment inside their own body.

Isolde recalled the words she had once heard in the depths of her consciousness.

“Do not reject the power of Decay. It was meant for you from the very beginning.”

Previously, she had assumed those words came from the lingering consciousness of the original Isolde.

Now, however, she could no longer be entirely sure.

This castle, Lia's body, the soul-stitching experiments Valen had conducted, and Isolde—the adoptive daughter he had brought back—might all be connected to the “she” he had spoken of.

Whether her absorption of the Decayed Residual Root was a mere coincidence or an inevitability remained completely unknown.

Isolde closed the black hardcover book and pulled out the torn page separately.

Valen was dead, and the entity hiding behind the power of Decay had not truly shown itself yet.

For now, the most important task was still to handle the things she could control.

She placed the books related to Red Kite on her left, and set the old black book and the torn page on her right.

“Lia.”

Lia, who was guarding the door outside the study, immediately stepped in.

“Miss.”

“Starting tomorrow, begin checking the castle for areas that require Immortal Hardwood.”

Isolde said, “Then, select the portions suitable for repairing the station. While you're at it, prepare a batch of ordinary tools, food, and old equipment to be used for constructing buildings and roads.”