The destination was a narrow, dark room.
This was an underground facility beneath the Royal Capital.
It housed activities that could not be made public, serving as the headquarters for covert operatives.
The room's only source of light was candles.
Of course, for the undead, this posed no inconvenience whatsoever.
Looking closely, one could make out the state of the room in clear detail.
About twenty humans were lined up, bound to chairs.
They were blindfolded with cloth.
Metal rings fitted to their limbs and necks had the effect of suppressing magic.
By disrupting the magical power within their bodies, the rings induced chronic malaise and hindered any voluntary use of magic.
These were precautionary measures to prevent them from deploying any strange techniques.
Those lined up here were spies from foreign nations who had infiltrated the Royal Capital.
Having blended in among refugees, they had come to steal top-secret information and technology from the Demon Lord's domain.
This was nothing unusual.
Infiltration by spies had been occurring for some time.
Recently, their numbers had increased dramatically, making them somewhat more conspicuous—that was all.
Their goal was not the defeat of the Demon Lord.
Rather, it was to use the information and technology they had acquired for the benefit of their own nations.
They were likely probing my weaknesses as well, though that was more of a secondary objective.
They had set their sights on the benefits of the Demon Lord's domain—the most powerful military force on the continent—and were trying to pilfer them.
To that end, the spies had skillfully concealed their identities and infiltrated the Royal Capital.
Weeding them out from among the harmless populace was difficult, but it was possible for the Demon Lord's army's covert operatives, starting with Luciana.
From a professional standpoint, it was not an impossible task.
And so, having been exposed and restrained, these were the ones gathered here.
It appeared that additional spies were being held in adjacent spaces as well.
With this many of them, wouldn't the operatives' activities start to suffer?
Perhaps it was time to consider a significant increase in personnel, or the establishment of a training institution.
"Oh, you've already come. As expected of the Demon Lord."
A cheerful voice called from the side.
It was Luciana, leaning against the wall at the edge of the room.
Beside her was a wooden shelf.
Stored there were tools used for interrogation and torture.
They were remarkably varied, prepared to inflict every conceivable kind of pain.
As the person in charge, Luciana was not in a position to carry out such work herself.
Normally, simply issuing orders would have sufficed, but she was taking the initiative and participating directly.
She would deliberately push them to their breaking point before using her charm to dominate them to the very core of their being.
When it came to such skill, one had to admit she was truly a former member of the Four Heavenly Kings.
I turned to Luciana, who was toying with the torture implements, and asked.
"What is the matter?"
"Well, that's the thing… I'm a bit troubled."
Luciana said, her brows furrowed.
She did not appear to be joking. It seemed she genuinely needed my help.
She began to explain the situation.
According to her, the people gathered here were behaving strangely compared to other spies.
They had been repeating the same incoherent ramblings nonstop, and even Luciana's charm had difficulty taking effect on them.
There was a possibility that some form of mental manipulation or special technique had been used on them, which was why she had called for me.
"I had a bad feeling about it, so I wanted you to take a look, Demon Lord. If I meddled carelessly and something went wrong, that wouldn't be good, would it?"
"Indeed, that's true."
I nodded.
Luciana's judgment was correct.
If it meant toppling the Demon Lord and claiming his wealth, the upper echelons of every nation would resort to any means necessary.
They would not hesitate to employ even inhumane forbidden techniques.
Given such circumstances, one could never know who was plotting what.
As long as humans could raise the banner of a just cause and claim the mantle of righteousness, they would immerse themselves in evil without limit.
This was something I had learned time and again as the Demon Lord.
Even the slightest sense of unease should be met with vigilance.