On July 12, around the time Jin finished his subterranean structure survey from outer space, Deus Ex Machina was in Radatora, the royal capital of the Darato Principality, holding a meeting regarding highway maintenance and construction.
"I am planning on a road width of six meters, utilizing crushed stone paving."
"That sounds wonderful, but roughly how long will the construction take, and how much will it cost?"
"As for this construction project, the World Conference will be covering the expenses, so please do not worry about that."
"I-Is that so?"
At least on the surface, that was the official stance.
Jin would already be receiving a reasonable compensation from each principality, so this arrangement was made out of consideration that having Maquina demand payment as well would strain the principalities' finances.
Furthermore, any reward Maquina received would ultimately end up in Jin's hands anyway, and receiving duplicate goods would only create storage problems.
On top of that, it had already been communicated to the relevant personnel in Avalon that Maquina would be doing this pro bono.
"As for the construction period, it will take one and a half days."
"...Pardon?"
Minister of General Affairs Ryuji F Katsuki of the Mimaka Principality wore a dazed expression, while
"Did you say... a month and a half?"
Chancellor Gix Yabo Miyata of the Darato Principality asked back in disbelief.
"No, one and a half days."
"H-How on earth could construction be finished in such a short period?!"
"Well, you see, we will be using specialized golems."
Maquina brought up the past construction project where Jin had compacted a road surface simply by marching a group of golems across it.
"We have evolved that method even further."
In Maquina's paving golem corps, the vanguard clears away grass and shrubs, while the following units level and compact the ground.
In truth, a squad of fifty Smith units had been mobilized for the task.
"Th-That must be quite a sight to behold..."
"Yes. This time, fifty units will advance in five ranks of ten abreast."
Since the highway is six meters wide, each unit is responsible for a width of sixty centimeters.
The first rank breaks up and removes large rocks.
The second rank clears grass and shrubs.
The third rank levels the road surface.
The fourth rank compacts the road surface.
The fifth rank performs the finish.
Since they carry out these tasks while walking, the road will extend at approximately four kilometers per hour.
"What do you mean by 'finish'?"
"They use the magi-craft called 'Bonding' to further increase the durability of the crushed stone pavement."
Incidentally, this method was viable because bedrock was exposed along most of the planned highway route. If there were an abundance of soil, an additional process to dig it out and lay down crushed stone would have been necessary.
That would require the extra labor of hauling in crushed stone, slowing their progress to under four kilometers per hour.
"Still, for a road to be built at walking speed is simply extraordinary."
"The site supervisor would only need to follow along on foot, then."
Minister of General Affairs Ryuji F Katsuki of the Mimaka Principality and Chancellor Gix Yabo Miyata of the Darato Principality were thoroughly impressed.
"Since preparations are required, we will begin construction around noon tomorrow. We will start from the Darato Principality side, which spans the longer distance, and finish on the Mimaka Principality side."
Because the construction would be completed in a mere day and a half, neither country raised any objections.
"Well then, I shall begin the preparations. What will you do, Ryuji-dono?"
Maquina offered to fly him back if he wished to return to the Mimaka Principality.
"No, if possible, I would like to see this construction through to the end."
"I see, very well."
Minister of General Affairs Ryuji F Katsuki of the Mimaka Principality and Chancellor Gix Yabo Miyata of the Darato Principality both insisted on following along behind the work crew in a golem carriage on the newly paved road.
Each of them would become the very first person to cross the national border using that highway.
Understanding such sentiments, Maquina agreed.
The following day, July 13, Jin's Doppel, Jin D, was in Quonale, the royal capital of the Mimaka Principality.
"Now then, I shall present you with the Weckener."
Just as he had done for the Noruha Principality, he gifted them an always-active Large Weckener.
"Ohh, this is magnificent!"
"As expected of the Magi Craft Meister!"
And then, Jin D delivered the subterranean water survey results—which was the primary objective.
"...And so, a water vein extending from Lake Yato to the sea exists along this line."
"Oh! Truly marvelous, Jin-dono!!"
"If we dig deep wells there, we can obtain water, correct?"
Duke Gaspar de Mimaka and Chancellor Moitz Myas Rohdai were overjoyed.
As long as water could reliably be secured, paying a minor development cost was no issue at all.
"Furthermore, there are mineral deposits in the eastern mountains."
"What?! You can discern even such things?!"
"A-As expected of the Magi Craft Meister..."
Those present were left in awe at the vast scope of Jin's survey.
"The most lucrative and useful location is right here. I believe magi-crystals and magi-stones can be mined here."
"That is wonderful!"
Minister of Industry Jintsuo Mihoyasu cried out in joy.
"And here, you can mine light silver."
In addition, Jin D pointed out the locations of deposits for iron, copper, and both gold and silver (these two precious metals can sometimes be extracted from the same ore vein) to conclude his explanation.
"Furthermore, I have a proposal."
Jin D spoke of a magi-device that produces fresh water from seawater and proposed that using it would allow them to expand arable land further inland.
"Looking at this map, development in the eastern direction appears to be lagging, so I believe it would be best to prioritize developing that region."
In the Mimaka Principality, southern coast development only reached as far as Darihida in the west and Gidami in the east; consequently, farmland ended there as well.
"Oh! If Jin-dono will assist us in advancing that, it would be a dream come true!"
Duke Gaspar de Mimaka was the first to express his gratitude.
"We should be able to manage the deep wells with our country's own technology, and the same goes for the mines once their locations are specified."
"Therefore, if Jin-dono could extend the South Coast Highway to the east, it would be an immense help!"
The Chancellor and the Minister of Industry bowed deeply to Jin D.
"Understood. Then let us proceed in that direction."
Here, Jin D decided to deliver a message on behalf of Deus Ex Machina, who was extending the South Coast Highway from the Darato Principality side.
"This is a message from Deus Ex Machina."
After offering that preface, Jin D began the explanation.
"Construction on the South Coast Highway from Somioshi toward this side is currently underway, and it should connect all the way to Darihida by roughly tomorrow evening."
The gathered dignitaries seemed utterly flabbergasted by the announcement.
"Wh-What did you say?"
"I-It will open that quickly?!"
Jin D then provided the same explanation Maquina had given in the Darato Principality.
"I-I see... So that is the procedure."
They managed to grasp the concept. However, the shock of having their common sense completely overturned seemed profound.
And so, when Jin D casually added,
"Incidentally, I can do the exact same thing,"
the color drained from all of their faces in unison.