"Nostalgia!?"
Jin blurted out the name before he could stop himself.
"Yes. Are you familiar with us?"
"I—I suppose so."
His voice pitched slightly higher than intended.
"I see. Well, we aren't a secret society, so I suppose it isn't unusual for people to have heard of us... Oh, perhaps you're a graduate of Avalon?"
"Lordtoss is."
Jin realized that Liira Madagas hadn't been told much about Lordtoss.
She had likely only identified him because his name had been called out while they were in the shop.
"Then it's only natural you would know of us," Liira said, appearing satisfied.
"So, what business does Nostalgia have with me?"
"Well, I apologize, but I cannot speak of that here. I can tell you more if you would be willing to accompany me to meet a certain individual."
"..."
Lordtoss turned to Jin for advice.
"What should we do?"
"Let's see..."
If the one inviting Lordtoss was indeed from Nostalgia, Jin figured there shouldn't be a problem. Nostalgia didn't harbor any dangerous ideologies.
"It might actually be easier to gather information if we go," Jin said.
Reiko offered her own suggestion at that point.
"Father, Lordtoss-san, why don't we first confirm if she truly is a member of Nostalgia?"
"Ah, you're right."
Jin turned back to Liira.
"If you can prove that you are truly a member of Nostalgia, we will accept your invitation."
"I see. In that case, please look at this."
Liira took out a single card and presented it.
"This is a Nostalgia identification card."
It was a business-card-sized plate made of thin metal. The owner's name and portrait were engraved into it as a watermark.
"It is certainly authentic," Reiko declared.
In this regard, Reiko was more reliable than Jin, who was still catching up after a three-hundred-year blank period.
"Thirty-six percent nickel, twelve percent chromium, with the remainder being steel. It's undoubtedly elinvar."
Elinvar was an alloy with minimal changes in elasticity regardless of temperature fluctuations. It was commonly used in precision instruments and springs for watches.
And it was Jin who had originally standardized its use.
By using an alloy with a combination and ratio that a typical engineer in this world would never think of, he had increased the security and credibility of the identification cards.
"Eh? How do you know that!?"
It was only natural for Liira, who was unaware of the history, to be taken aback.
"Er, let's save that explanation for after we meet the person you want us to see. Does that work?"
Jin guessed that the person was likely an executive of some kind.
"...I understand."
After a moment of thought, Liira nodded.
"That is acceptable."
Jin nodded back.
"In that case, where should we go? Do we need any preparation?"
Liira shook her head at the question.
"No, it won't be any trouble. It's quite close."
With that, she stood up and inserted the identification card into a slit beside the door behind her. It seemed the watermark was mechanically scanned to act as a key.
It's just like an ID card, Jin thought as he watched.
"Oh?"
The door opened silently.
"Would you please come this way?"
"...Let's go."
Jin secretly activated the barrier function of his Fellowship Bracelet.
Additionally, Reiko raised her output from her usual one percent to ten percent, silently entering a state of combat readiness.
Lordtoss also remained vigilant, and Hope switched to a state of high alert, utilizing his detection functions to their full capacity.
With their guards up, the group passed through the door.
There was another door inside, where Liira used the identification card once more.
"Whoa."
Beyond the door was, of all things, a Warp Gate. It was a somewhat large model, seemingly capable of transporting about six people at once.
Jin noted that it was the same model he was familiar with.
"We will use this Warp Gate, so the trip will be instantaneous."
"I see."
Both Jin and Lordtoss accepted this.
"Now, please step inside with me."
"Understood."
The five of them—Liira, Jin, Lordtoss, Reiko, and Hope—stepped into the Warp Gate.
Their field of vision shifted in an instant, and they found themselves at the receiving Warp Gate.
"Please, this way."
As they exited...
"Good work, Liira....You've brought quite a crowd, haven't you?"
A woman, presumably another member of Nostalgia, was standing there. She had dark blonde hair and blue eyes, and appeared to be roughly the same age as Liira.
"Yes. This is the person I was instructed to find, along with his companions. They both seem well-acquainted with Nostalgia, so it's fine."
"I see, then that's all right."
The woman then turned toward Jin and the others.
"Welcome to the Nostalgia headquarters. I am Arietta Eoreal, the Warp Gate Management Department Chief. I will be your guide."
"The headquarters?"
"Is this really the headquarters? Is it alright to tell us that?"
Jin didn't know where the current Nostalgia headquarters was located, and neither did Lordtoss.
However, Liira and Arietta nodded with confidence.
"Yes. As long as you don't know where it is, there is no problem with telling you its name."
Jin conceded that she had a point.
That said, if Laojun used a magi-detector to search for Jin's magic pattern as a marker, the location would be identified immediately. Or rather, it wouldn't be surprising if Laojun already knew the location of the Nostalgia headquarters.
"More importantly, I would like you to meet the person who ordered us to bring Lordtoss-sama here."
"Ah, understood. That's why we came in the first place."
"Thank you. This way, please."
With Arietta leading the way, the group walked down the corridor in the order of Jin, Reiko, Lordtoss, Hope, and then Liira.
Since there were no windows at all, it was impossible to tell where they were. It was unclear if they were underground or on the surface.
After walking about twenty meters down a straight corridor, they encountered a metal wall and a metal door.
"This is the place."
Arietta used her identification card to open the door.
Inside stood four golems, presumably for security as they appeared to be combat-oriented.
"I am... glad... you... could join... us."
A feminine voice echoed from the back of the room.
Looking over, Jin saw a large desk covered with a black cloth. The voice was coming from behind it.
Reiko stepped half a pace forward.
"You are..."
Jin only thought that the voice sounded familiar, but Reiko immediately saw through the identity of the speaker.
"You're Elena-san, aren't you?"