The < is descending steadily.

Again, at the 20 meter mark, the shaft of the pit is shifted.

(Is 20 meters the dividing line?)

(It seems so.)

And descending again.

Each of us has 200 meters of rope made of < thread, so there is plenty of room for now.

The eight spiders continued their descent without any problems.

After descending a total of 100 meters, they encountered something they had never seen before.

It was a .

It was not strong, but it prevented wild animals, insects, dust, water, etc. from entering.

（It was a force field.)

The closer you get to the warding, the more repulsive the force becomes.

The maximum output is about 10G.

The maximum output is about 10 G. Aside from large monsters, the only ones that can enter this far are those of medium size or smaller, so the strength of the wards is probably sufficient.

However, the Shinobi troops with their force field generators can break through with no problem.

What worries me are the sensors.

（I guess that's where the seven tools the master gave me come in again.)

Shinobi I took out the second tool after the rope.

<.

In other words, a sensor that detects the presence or absence of a sensor. The name is Jin.

Many magical sensors, like electrical sensors, require <> magic power.

This sensor detects the standby magic power.

Incidentally, a purely mechanical sensor ...... such as a switch that turns on when it is caught by a string, or a switch that turns on when a certain weight or more is placed on it, cannot be detected.

(Okay. According to this, there is no sensor that can detect magic power.)

Shinobu I judged so and used the force field generator to pass through the boundary.

（Oh, the atmosphere has changed.)

From there, the walls of the ventilation openings are made of beautifully polished stone.

I guess they don't need to disguise it as natural stone any more.

And this time, the axis shifted not 20 meters, but 100 meters.

The rope length is 200 meters, which is enough to handle the situation.

The group continued to descend.

The same structure as before continued.

After descending a total of 900 meters, they finally encountered a material obstacle.

With such a long ventilation opening, ventilation in this facility is naturally not left to nature, but forced ventilation.

In other words, there was a magi-machine that pumped the air.

(A ventilation blower.)

（The wind speed is about 20 meters per second.)

(After passing through here, we will finally reach our destination. Shinobu, Shichi and Hachi, stay here in case of emergency.

(Understood.)

The six now formed Shinobi units force their way through the blower.

It was easier only because there was no fan to rotate as it was done by magic.

Also, the small size of the shinobi unit meant that the air resistance was small, and they managed to get through the blower.

And now, finally, the underground city.

（Let's be more careful.)

(Understood.)

The six of them cautiously looked around through the intake ports of the . Of course, they were invisible.

He continued his observation for about 30 minutes.

The ventilation facility seemed to be located in a place not in the center of the town, but not at the edge either, and what came into view was a reasonably well-developed townscape.

The view we had was of a reasonably neat townscape, with a reasonable sense of life.

There are two things that bothered me about the Shinobi Unit.

First, it was dimly lit. It was not pitch-dark, but not bright either.

It was about the same brightness as just after sunrise.

And secondly, I saw only automata and golems, but no human beings during the 30 minutes I was there.

(...... It's time to report. (It's about time for me to report........)

In the meantime, as the time for the regular contact agreed upon with the old man was approaching, Shinobu I summarized the contents of his report.

He then moved the ventilation equipment to the roof of the building about 50 meters away as the transmission point.

At this time, he decided to use the third of the <>, the <>.

This was a small-scale version of the that had been deployed above the former Leonard's Kingdom, and it deployed a lower false image above the <.

In a sense, it may be the most ninja-like equipment.

The disadvantage is that it is impossible to hide if there is a camera right beside or below you, but since surveillance cameras are usually installed to look down on you from above, and since they are also <>, they are very reliable.

(It's regular time. (Sent from ......)

* * * *

On Horai Island, we have received a regular message from Shinobi I, and the analysis of the message has begun.

The analysis, however, is in Japanese, and the contents can be viewed immediately since they are merely highly compressed.

Jin and the Jin family confirmed the contents of the report displayed on the large magic screen.

"Fuun ......"

"Two points of interest, huh?"

"Yeah. Yeah. The darkness and the fact that I haven't seen any humans around.

< are sharing their opinions.

"I still don't understand why you don't see anyone.

Turles said.

"<> are basically reclusive. And if they don't go outside, dark lighting is probably sufficient.

"Haha, I see."

< Turles had a point. But...

"......No, don't get me wrong.　I'm just pointing out that this is a possibility, and I too feel that this situation is unusual.

The <> added, causing Jin and the others to ponder again.

"I guess we'll just have to wait for the next contact. ......"

"Yes."

"Yes." "Mm."

For the moment, they did not use the old man's "peepers" to avoid being noticed.

Of course, he would use it whenever necessary, but for now, it was time to wait for the report of the "Shinobi Unit".

* * * * * * * * * * * *

(End of report communication. We are going to move a little.)

It would be dangerous to stay in the same place if the communication had been intercepted and the source of the transmission had been identified.

That is why Shinobu Ichi ordered them to move.

However, it seemed that this was a groundless fear, and after 15 minutes there was no major change in the town, and no search parties appeared.

（It seems that everything is fine. But we can't let our guard down yet. We'll move on to the next stage with caution.)

(Understood.)

<