I was guided by Milia-san and the guild master to the basement of the Adventurer's Guild headquarters.

　The ancient ruins of the basement as a whole had a rundown atmosphere, but they were cleaned up nicely.
　There must be people coming and going on a regular basis.

　After advancing through the corridor for a while, I found a large door at the far end.

''Ko-san, over here is the central part of the Adventurer's Guild. Are you ready to prepare your mind?
Is ...... a white thing you need to prepare yourself for?
'Hmm, I don't know. Ordinary people might be surprised, but Ko-san is special in many ways. ...... Well, let's go inside anyway, shall we? It's good, isn't it, Guildmaster?
Of course. I look forward to working with you, Dragonslayer. ......!

　We walked into the room.
　There was a strange scene.
　One, two, three ...... countless translucent message windows were floating in the air, one, two, three ...... countless times.
　However, nothing is displayed in the message window.
　It looks like a malfunctioning computer monitor.
　There was a square device the size of a washing machine in the center of the room, and the guild's employees were holding their heads around it.

''No. ....... No matter how I try, I can't get it back: ......'
What the hell is going on?
'We don't know the cause, we don't know what to do about it ....... There's nothing we can do about it at this point: ......!

　Apparently, the restoration process wasn't progressing at all.
　Eventually, one of the guild staff noticed my presence.

''Hm?　There you are, Milia, with the guildmaster and ...... uh, who is that?　It doesn't look like it's one of our employees: ......

　Now, how should I introduce myself?
　When I was lost, Milia-san opened her mouth instead.

''Ladies and gentlemen!　Someone who might be a savior in the bleak recovery process!　...... I'm Kou Koussaka, the Dragonslayer and Master of the Ancient Ruins of Onen!　Please welcome them with a round of applause!　Click, click, click.

　Crackle.
　When Miria-san clapped loudly, the guild staff caught on and clapped their hands with a crackle.

''......《Dragon Slayer》is a new adventurer who's been the talk of the town lately, right?
Does that mean the Saviors are going to fix the device?
Please, do something!　At this rate, the Adventurer's Guild is finished!

　Apparently, the guild staff were pretty much cornered and readily accepted my presence.
　It's a bit surprising.
　I had a feeling they'd tell me to keep my mouth shut if I was an outsider.
　I'm sure he's grasping at straws.

　Well.
　So let's get started.

　The first thing I did was to speak to the guild master.

'Who is the master of this ruin?　...... Who are you becoming?

　Oops.
　I hurriedly rephrased my words as my quirks made me feel respectful.
　The Guildmaster nodded deeply before answering, ''The Guildmaster is supposed to take over from generation to generation.

''The guildmaster of the generation is supposed to take over, but what about it?''
Can we temporarily overwrite the mastery of the ruins?
That's all well and good, but since the device is shut down in the first place, I'm afraid you're not going to be able to transfer your mastery of it, .......
No, I think I'll be fine.

　Do you remember when we took the lab of the Great Sage Mobius?
　At that time, I used a skill called 【Master Code】.
　Its effect was to 'rewrite the master of the ancient ruins'.

　I touched my hand on the device and activated the 【Master Code】.
　I could hear a voice in my head.

''Activate 【Master Code】, forcibly take away the master rights of the ruins.
　...... process ends. The master of this ruin is now Kou Koussaka.''

　All right.
　So far so good.
　Next, when I activated 【Grasp the Ruins】, information about this ruin flowed into my brain.

　...... I see.
　I now know why the Adventurer's Guild's device was shut down.
　To put it simply, it was because it was hacked.

　* * *.

　This was found out through [Ruins Seizure], but even in the distant past ...... 5,000 years ago, the profession of 'adventurer' seemed to have existed.
　It seems that the people of that time also ran adventurer's guilds, using the equipment of the ruins.

　Eventually, the ancient civilization was destroyed by a disaster, but about 200 years ago, these ruins were accidentally discovered and the Adventurer's Guild was established as we know it today.
　The system of the ruins was working normally until today, but just a few hours ago, it seems that the system was illegally accessed by someone and caused an error.

　We are wondering who and how they managed to interfere with the system, but rather than looking for the culprit, we must first repair the system.

''Do you want to establish a magic network between the main ruins and the Onen ruins?
　The backup data of this site is stored in the Ohnen site.
　It is possible to restore the system of this site by using the backup data.

　I'm not sure what a magic network is, but is it like the Internet?
　It doesn't seem like a bad thing, and I order it to be done.

　A few seconds later, I heard more voices.

'The network is complete. We will then begin to restore the system.
　The ............ system has been restored. This site will be returned to normal operation.''

　You're early.
　It hasn't even been a minute.
　Anyway, it looks like the problem at hand is solved.

　I turned to the Guildmaster.

''It's done. Now the Adventurer's Guild system should be back to normal.
'What a great ......!　You think putting your hand on the device was enough to fix it?　I can't believe it: ......!

　The Guildmaster had a questioning look on his face.
　The surrounding staff members also tilted their heads, but soon, as letters and symbols began to appear in windows floating around the room, they were surprised.

'It's true!　We're back in business!
'Thank goodness ......!　Dragonslayer, you are the savior of the Adventurer's Guild!
'Thank you!　Thank you!

　The guild staff seemed to be very happy and even cried tears of joy.

　I'd like to say that this is all settled ......, but I still have one more job left to do.
　Who has been interfering in the adventurer's guild system?
　We have to find out who's behind this.

　I heard the voice in my head again.

"We have confirmed unauthorized access to this site. Do you wish to perform an interception and tracing?

　Naturally, the answer is yes.
　Apparently, we're going to be able to face the culprit sooner than we thought.

　This is almost like a hunch, but I think the culprit is a member of the Mercenary Guild.
　It could be because the Adventurer's Guild is a business enemy to the Mercenary Guild ......, but the image of the Mercenary Guild is very bad in my mind to begin with.
　The mercenaries are causing trouble here and there, and even Surie's branch head was a member of a secret society called The Breath of the Ancient Sage, and didn't think anything of other people's lives.

　...... While I was thinking about that, I completed the reverse detection.