After the couple walked away, Jin and Elsa spoke in hushed tones.
"What did you make of that just now?"
"...No matter how you slice it, something fishy's going on."
"Yeah....'Participating,' huh? The fact that they said that after looking at Hope must mean there's something involving golems."
"Mm, agreed."
However, they had no idea what that something actually was.
"Want to look into it?"
"Yeah, I'm curious."
With Elsa on board, they decided to start by keeping an eye on the pair from earlier.
The couple had approached a party of three seated near the middle of the dining hall.
"...They seem kind of unpleasant."
"Yeah."
While they couldn't make out what was being said, crude laughter echoed across the room.
Shortly after, the three and the couple left the dining hall together.
"Hmm... What on earth is that about?"
At that moment, Reiko, blessed with sharp hearing, spoke up.
"Father, those people mentioned that they were heading to the 'underground event hall.'"
"An event hall? Is something going on in the basement?"
"I cannot say for certain."
Even Reiko could not glean details that had not been spoken aloud.
"It smells suspicious, somehow."
"Mm."
"Father, Elsa-sama."
Reiko warned that pursuing the matter any further might prove dangerous.
"If you intend to investigate, please swap with your Doppels."
"Good point."
Following Reiko's advice, they briefly returned to their room.
Laojun dispatched a Warp Gate there, which Jin and Elsa used to return to Hourai Island for the time being. In their stead, they sent in their Doppels.
Reiko then temporarily dismantled the Warp Gate.
All told, it took five minutes. Their preparations were complete.
They headed back to the dining hall. Since golems seemed to be the crux of the matter, Hope accompanied them as well. Reiko, of course, was right by their side.
The dining hall was emptier than before.
"Now then, where should we start?"
Having switched into their Doppels, their enhanced hearing allowed them to pick out conversations throughout the entire dining hall if they so desired.
<Tonight has an interesting lineup...>
<I hear it's quite thrilling...>
<Seems it was worth coming after all...>
Overhearing scattered snippets like that, they began to piece together that some sort of illegal—or borderline illegal—event was taking place underground.
Thus, the four of them—Jin D, Elsa D, Reiko, and Hope—decided to tail the trio who had been having that conversation.
The three made their way toward a door that appeared to lead down into the hotel's basement.
A guard was stationed there, and after a brief exchange, they were permitted through.
When Jin D and the others approached...
"Excuse me, guests, do you have a letter of introduction?"
The guard stopped the four of them and inquired.
"No, we don't have one, but will this suffice?"
Jin D handed four gold coins to the guard. The man grinned and pocketed them.
"Much obliged. If it's your first time, please put these on."
He handed each of the four a mask designed to conceal the area around their eyes. Wearing them would apparently make their facial features difficult to discern.
"Still, are you sure about this? It might be a bit too intense for the little lady, you know."
Having been addressed about Reiko, Jin answered,
"Ah, she'll be fine. This child is an automata."
Upon hearing that, the guard stared at them with wide eyes before ushering the group through a different door from the one the previous three had used.
Beyond the door lay a staircase descending into the depths.
It was somewhat dim, but each step was broad enough that there was no danger of losing one's footing.
Even so, the descent dragged on. It seemed to plunge quite deep beneath the earth.
"Father, we have descended at least 100 meters underground."
"That deep?"
The thought of how tedious the climb back up would be briefly crossed his mind, but Jin quickly reminded himself that his current body was Jin D.
Even so, he couldn't help but fret over how the other guests were supposed to manage the trek.
"What in the..."
The moment they pushed open the heavy door at the bottom of the stairs, Jin D, Elsa D, and Reiko were seized by men flanking both sides of the entrance.
"Don't move, golem! If you take one step, we can't guarantee your master's safety!"
Faced with such an overt threat, Jin D pretended to comply for the moment and signaled not to make a move... primarily directing the warning at Reiko.
"...Listen, don't move."
(I'm glad I came as Jin D. If this had happened to our real bodies, Reiko would have flown into a violent rage...)
It seemed that anyone entering through this particular door was flagged as a person of interest.
The proof was that the couple who had spoken to Jin earlier were restrained in the exact same manner.
"You're the ones from before."
"Oh, what a coincidence."
As Jin D and the woman exchanged words, one of the men sneered,
"Oho, so you're acquaintances? Then we definitely can't let you walk out of here."
"Huh? No, we just exchanged a few words in the dining hall."
"That's right! These people have nothing to do with this!"
However, the man who appeared to be their ringleader scoffed,
"Like I'd buy that....Conveniently, you brought a golem along. Perfect—we'll put it to use in tonight's entertainment."
He eyed Hope as he spoke.
"Entertainment?"
Jin D was completely in the dark. He turned to the woman from earlier to inquire.
"Pardon me, but I don't quite understand what's happening here. Could you explain the situation a bit?"
"S-Sure, I suppose... Though I must say, you're remarkably composed."
Even while restrained, they were operating Doppel bodies, meaning not a single person in Jin's group felt the slightest sense of danger.
"W-Well, whatever....Never mind about me. This is an underground arena where underground gambling takes place."
"Underground gambling?"
"Yes. I said it's an arena, didn't I? They pit golems against each other in battle, and the audience places bets on the outcome."
"I see... Does that make you some kind of investigator, then?"
"...You really are unshakeable. Well, something like that."
Now the pieces fell into place.
Illegal gambling was being run beneath the surface. In every era, illicit schemes like this never truly disappeared, Jin mused.
"...Well, that's how it stands. If you three pay up, I might just let you walk out of here in one piece."
By "you three," he presumably meant Jin D, Elsa D, and Reiko.
"But that golem of yours is going to be performing in the main event."