Yumis Isle had discovered a hidden door.
Rather than opening it rashly, she decided to call in an expert from Avalon.
As luck would have it, Deus Ex Machina was currently visiting and arrived alongside Squire Rei.
Squad Leader Northernon Quetos accompanied them as well.
"Lord Maquina, thank you for coming all this way."
Yumis bowed respectfully.
"No, think nothing of it....So, this is the hidden door..."
"Whose work could this be... or rather, what manner of beings built it?"
Northernon Quetos tilted his head in wonder.
Laojun and Mentor decided that, at this point, Maquina had no reason to conceal the truth any longer.
"I believe it was built by a race with super-advanced technology that existed in this world in the ancient past."
"Wh-what?!"
"The magifortress in the Kingdom of Franz is another example. Avalon itself was almost certainly left behind by such beings."
"I-is that so..."
Being a logical thinker, Yumis Isle managed to process and accept the explanation.
"In that case, what lies beyond?"
Northernon asked eagerly, but Maquina shook his head.
"That, I cannot say. It appears to be an abandoned ruin, however, so there might not be anything of real significance... or there just might be."
"I see."
Even as he spoke, Maquina ran his hands along the wall, probing various spots.
"'Sonar'... Yes, as expected, there is an open cavity on the other side."
He had already confirmed this beforehand using Laojun's Peeper, but he staged the investigation to make it look like a fresh discovery.
Naturally, he also already knew there was no immediate danger.
"Now, as for opening it... Hm? Ah, if I press here, like so..."
Maquina applied firm pressure to a specific section of the wall. The stone gave way with a soft click, sinking inward to reveal a switch.
"Ooh?"
"As expected of Lord Maquina!"
"No, I simply traced the flow of mana through the wall."
With that modest reply, Maquina cautiously engaged the switch.
The hidden door slid open without making a single sound.
"Incredible!"
"So beyond this lies the true ruin..."
Northernon Quetos stared in admiration, while Yumis Isle peered cautiously into the darkness beyond.
"Indeed. Let us have Rei scout ahead first....Rei, if you would."
"Understood."
With that brief acknowledgement, Squire Rei stepped across the threshold without a trace of hesitation.
After spending about ten minutes searching the interior, she returned to make her report.
"There is no danger."
"Very well, let us take a look," Maquina said.
"Right away, sir!"
Northernon Quetos answered eagerly, pushing past the doorway before anyone else.
"Good grief... The squad leader never changes..."
Watching him dash ahead, Yumis Isle let out a weary sigh.
"Is Northernon-dono always like that?"
"Y-yes. When the situation turns dire, he shows remarkably calm judgment, but under normal circumstances, he's..."
Yumis pressed a hand to her forehead.
"Well, as long as he is dependable when it truly matters, isn't that enough?"
Offering that bit of reassurance, Maquina stepped through the doorway. Squire Rei and Yumis Isle followed close behind.
"This place is..."
The walls, the floor, the ceiling—every surface felt completely alien compared to the rooms they had passed through before.
It was roughly the size of an elementary school classroom, built with an unusually high ceiling.
Furthermore, there were no visible exits or entrances aside from the door they had just used.
And beyond that...
"It is entirely white. Does the color hold some special significance?"
"It was likely just the preferred aesthetic of the race that lived here in the past."
Maquina gave his assessment.
Since the "room" belonging to Elder No. 700672 was similarly stark white, Maquina reasoned aloud that such an inclination was entirely plausible.
"I see..."
Yumis Isle gently laid a hand against the wall.
"It does not feel like metal. It lacks that coldness. But it isn't wood, either. Nor does it look like a simple coat of paint."
"It is resin," Maquina supplied the correct answer.
"Resin?...Do you mean something like pine resin?"
Even in Avalon, magi-resin was not yet widely known.
However, pine resin was literal resin, and magi-resin was fundamentally the same category of material.
"Yes. More precisely, it is quite close to magi-resin."
Being magi-resin, any scratches or holes could easily be mended with magic.
Even crafting a small wall shelf would take only a matter of moments.
"It can also be utilized like this....'Forming.'"
"Ah!"
As Maquina cast the engineering magic, a portion of the wall warped and opened up, leaving a clean recess behind. Nestled within was a concealed cupboard.
"Under normal circumstances, one would never notice it."
"I-indeed! As expected of Maquina-dono! Magnificent!!"
Northernon Quetos showered Maquina with lavish praise.
Opening the cabinet's double doors revealed a single small magi-device sitting inside.
"What could this be?"
Northernon Quetos reached out to take it, but Squire Rei caught his arm, holding him back.
"Do not touch it carelessly. That is a trap."
"A-a trap?!"
Startled by Rei's sudden warning, Northernon Quetos asked nervously,
"Wh-what happens if someone touches it?"
"Well, as to that..."
Thanks to the short-range Peeper, Maquina already had a good idea, but explaining how he knew would be far too troublesome, so he kept his answer vague.
"Shall we test it?"
With that calm declaration, Rei deliberately reached out and grasped the magi-device.
"Whoa?!"
"Eek?!"
The instant her fingers closed around it, an electrical discharge reaching approximately ten million volts erupted from the small magi-device.
It was a lethal surge of magic that made one shudder to think what would have happened to anyone other than Rei.
"W-was that the trap just now...?"
Northernon Quetos asked in a hushed, trembling voice.
"Most likely. That said, the current itself appears to have been extremely low, so an ordinary person would likely have suffered nothing worse than losing consciousness."
Maquina had accurately analyzed the spell in that single brief moment.
"And once the trap is either bypassed or endured..."
Something occurs, Maquina concluded.
True to his prediction, deep within the recess behind the first compartment, a second hidden cupboard slid into view.