Hourai Island, a solitary island floating in the Blue Marine. This was the base of the Magi Craft Meister, Jin.
Upon returning to his laboratory, Jin stood aghast.
"It’s in pieces...! You’ve got to be kidding me!"
The magi-crystal that was supposed to contain the information he had extracted from Marcello via Trans Info was shattered.
"It must have been that golem’s blow..."
When he had taken the hit from the Unifilar’s Universal Golem, Jin had been safe thanks to his reinforced suit, but the magi-crystal he’d tucked into an external pocket had apparently absorbed the brunt of the impact. Choosing a more pliable fabric for that pocket specifically to allow for movement had backfired.
"It's too late to try again now..."
Since he had left the rest of the cleanup to Reinhard, he had no choice but to give up on that lead for now.
"Well, if there's a next time, I'll just have to be more careful."
Shifting gears, Jin began his analysis of the enemy golems.
The first wave of fifteen combat golems held no secrets. Their structure was familiar—they were old-fashioned models that served as the prototypes for the likes of Gon and Gen.
However, the combat golems that had appeared later were a different story. They had displayed power that was, in its own way, a match for Land 50.
"Hmm, even the internal structure is different. They actually have a proper skeleton."
He identified a hardened steel skeleton. However, the joint structure didn't come close to the ones Jin designed, and the quality and application of the magical muscles were incomparable.
"But I bet it's because of these."
Jin pulled out four gemstones. They glowed light blue under sunlight and green under artificial light. As far as he knew, there was only one kind of gemstone with those properties.
"Elradrite, huh."
These gems, equipped at key points in the limbs, amplified magic. The standard increase was twentyfold.
"They used these to produce power on par with Land."
However, generating that much output from ordinary materials put an immense strain on the frame. Sure enough, the magical muscles had significantly deteriorated.
"I see. They have to perform maintenance every time they use full power. What a hassle."
The critique was perhaps a bit harsh. After all, the enemy didn't have an environment where they could use rare materials as freely as Jin did.
"But that's a massive mana tank. Isn't it about ten times larger than a normal golem's?"
The space in the chest and abdomen was almost entirely occupied by the mana tank.
"Hmm, if Elradrite amplifies magic, they shouldn't need such a huge mana tank... unless?"
One possible reason occurred to Jin. Holding one of the Elradrite stones in his hand, he cast a spell to produce light.
"Light."
Normally, this would produce a glow roughly equivalent to a hundred-watt bulb, but instead, the room flared with a blinding flash, as if a high-powered strobe had gone off.
"Whoa!"
Blinded, Jin dropped the Elradrite.
"Father, what happened!?"
Reiko came flying into the room in a panic.
By then, the Light spell had already expired, so Reiko could only ask Jin what had occurred.
"No, just a little experiment. Ahaha, I see, so that's how it works!"
Jin burst into laughter. Reiko watched him with a worried expression.
"Father...?"
"Ah, sorry. I was testing the claim that Elradrite amplifies magic. It does amplify it, all right—but it requires a proportional amount of mana to do so."
During the experiment, Jin had sensed that the mana consumed for the Light spell was roughly twenty times higher than usual.
"In other words, the power of the magic might become twenty times stronger, but it also drains twenty times the mana. If you don't have a massive reserve to begin with, there's not much benefit."
Unless one possessed a massive pool of mana like Jin, or could supply it inexhaustibly like Reiko and the others, it would be a one-shot gamble. That was why the combat golems required such enormous mana tanks.
By Jin's estimation, if they had continued wrestling with Land for more than ten minutes, they would have probably run dry and ceased functioning.
"Well, I'll need to do more detailed experiments, but that seems to be the principle. I'll leave the further validation to Laozi."
Once he had settled the matter regarding the Elradrite, Jin decided to discuss the topic he had started to bring up with Reiko the previous day—namely, the Warp Gate rampage.
"Basically, I want to create a Warp Gate that doesn't require a receiver on the other end," Jin explained to Reiko.
"That would be wonderful. We could infiltrate an enemy base directly."
"Exactly. Travel would become incredibly easy. If we could warp to any location with a standard Warp Gate and then set up a permanent one there, it would change everything."
"It truly would."
And so, the two who had actually experienced being warped by a rampage—Jin and Reiko—began a detailed study.
With Laozi's support, they began to formalize the theory. For an entity with Laozi's processing power, constructing a theory for the Warp Gate while simultaneously validating the Elradrite was a simple task.
That was when Anne arrived. Anne was currently working as an automata assigned to Laozi, specifically acting as a logical checker for the plans Laozi formulated. Since she possessed a different thought process, she was invaluable in this role, even if her lower processing power meant she was often occupied for long periods.
"Master, Big Sister, what are you doing?"
Lately, Anne had taken to calling Reiko "Big Sister" without hesitation, even though their appearances suggested the opposite.
Jin explained the project to Anne as well. She listened and then remarked:
"It will be necessary to define a coordinate system to specify a single point in space."
Anne was capable of this kind of logical deduction. In contrast, Jin relied more on intuition, a trait Reiko and Laozi had inherited.
"I see, that's true."
Jin then recalled his high school studies. When it came to a three-dimensional coordinate system, the first thing that came to mind was the XYZ coordinate system—length, width, and height.
"There was something else... right, polar coordinates. Azimuth, altitude, and distance, I think?"
He was unsure of the exact terminology, but the concept was sound.
"In this case, polar coordinates with the sending side as the origin might be more effective."
If the sending Warp Gate was the origin, they would only need to determine the distance, direction, and altitude.
"In that case, we will need to convert the coordinates of known locations into polar coordinates," Anne advised.
"Yeah, we'll need a dedicated calculation device... a control core."
Slowly, the concept for the control system took shape. However, the crucial part remained: whether they could actually manifest the exit point at the destination.
As far as Jin understood it, the principle of a Warp Gate was to connect two different points. It wasn't a matter of deconstructing atoms and reassembling them at the target.
"Hmm, the main role of the receiving side of a Warp Gate is to act as a beacon. It's a marker that can be identified from a distance. In other words, the receiving side doesn't actually need a physical frame."
The only reason the receiver looked like the sender was so it could function as a sender for the return trip.
"If it's one-way, we don't need a frame. And if we can remotely project the magic circle or magi-formula that serves as the beacon..."
Jin fell into deep thought.
"Father, determining the distance is the hardest part, isn't it?" Reiko noted.
She was right. Determining the direction could be intuitively understood, much like aiming a railgun. But the distance was another matter entirely.
"True. There are three ways I can think of right now," Jin said. "The intersection of straight lines extended from two points..."
"And the amount of mana used for the transmission," Reiko added.
"The equilibrium point between gravitational and repulsive forces," Anne offered brilliantly. It was the same principle used for barriers.
"Either way, long distances will be difficult. We'll need to start with targets within visual range."
It seemed they couldn't just jump from Hourai Island to the Celuroa Kingdom on the first try.
With that, Jin decided to start building a prototype. For the sending side, he would modify a standard Warp Gate. Normally, a gate was connected to its twin by a faint flow of mana. Instead of this faint connection, he would use a powerful flow of mana to construct a magic circle at the target point.
"It will depend on how much we can simplify that magic circle," Anne noted.
With Anne's assistance, prototype no. 1 was completed shortly after noon.
Jin warped to Kunlun Island to have lunch with Elsa. Reiko accompanied him, while Anne stayed behind to perform final checks before the test run.
"Jin-nii, welcome. Thank you for saving Rai-nii last night. Is that why you're a little late today?"
"Yeah, I just had some things I couldn't step away from."
Elsa glared at Jin as he made his excuse.
"You really are such an engineering nut, Jin-nii."
Reiko then spoke up in his defense.
"It is because you wait for him, Elsa-san, that Father actually makes sure to eat his meals. Otherwise, he would nonchalantly skip two in a row. Even today, he's practically been up all night."
"Jin-nii, that’s no good. It’s bad for your health."
Rebuked by both Reiko and Elsa, Jin scratched his head sheepishly.
"I-I get it. I'll be careful," he apologized.
He then gave Elsa a brief account of what had happened the previous night, though he made sure to keep quiet about the fact that he had actually been hit.