“What’s the issue?”

Jolyne’s voice came through the communication Cast as a perimeter formed outside the defensive cannon.

“These cannons…they don’t really look like anything from your world, right?” Wu asked, glancing towards Lera who leaned over the communication Cast, her black and white hair scraping against its surface.

“What are you suggesting?” Jolyne asked.

“Augen mentioned that these country-level defensive Casts were left behind as remnants from the War of the Third Millenium…but I thought the War ended with the execution of the third savior?” Wu asked, and he turned with Lera to see Joseph ushering the King of Varous out of a special chariot.

“Well...That was only partly true.” The King said, “According to recorded history, the Third had help, not just from people of this world. Some say that after his passing, he left behind his people, which continued his work to ensure the demonic forces shall never return again.”

“And thus explained the revolutionary manuscript…” Lera continued.

“Are you suggesting that more were summoned by the tablet?” Wu asked, “More than just…the Savior? Is that even possible?”

“That was the suspicion of the scholars, yes. Or, it was suggested that the Third simply passed on the knowledge that was obtained from...unknown sources.” The King responded.

“Great. Guess we will just have to take it one step at a time then.” Wu rubbed his chins and gestured for Lera to step towards the bottom of the defensive tower. If more individuals were brought from his world after the Third Savior's time, that explained the design of the towers.

But if that’s the case, could he technically be considered as someone who was just brought over too? Even if Lera saw the instructions on the tablet as bringing over the Fourth Savior, who could have known if he was actually supposed to be the one? Maybe he wasn't supposed to be the Savior after all.

That’s just not…a very helpful way of thinking, is it?

Wu shook his head and forced himself to focus. Apart from how not just people, but perhaps ideas and items could also be brought over, Wu just doesn’t want to think with that self-deprecating mindset anymore.

After all, reality itself is deprecating enough.

“Alright, let’s try this new strategy.” Wu nodded towards Lera, who knelt down and set up a perimeter with her Cast array. Then, a light semi-transparent membrane rose up and wrapped around the entirety of the defensive tower.

“You sure this is going to work?” Lera asked.

“Well…it’s a classic strategy on my world…” Wu smiled, glancing at the membrane where small blue circles started forming over its surface, “It’s not exactly something new here either. We are simply detecting the output from the defensive Cast with the rest of its network before duplicating it and sending out the false signal, like what we did with the communication Cast.”

“But expanding it out to beyond what we have on the workshop table…” Lera continued before waving her hand, and a duplication of the signal going out from the defensive Casts became projected outwards, following the same trajectory as before.

Really, this was the same technique as what they performed on the communication Cast, just applied to a more generalized context. However, Lera still felt her heart pounding in her chest.

Then, a dim shadow formed just underneath the thin membrane, as Wu created a Void Domain with a thickness of a few inches to act as a shield between the inner tower and the outside world while holding the previous steady signal on Lera's part.

None of these new techniques was ground-breaking, but rather incremental improvements and innovation that stemmed from what they had in the past. Such is the way science moves forward.

By combining Void Domain and anti-Void Domain, projected at different distances radially from Wu’s body, he can create a highly flexible shield layer made out of Void Domain, without hindering the ability of anyone within the shield to use their Wave.

A more elegant solution to the same problem as before, and now, they can use it to freely experiment on the defensive Casts.

“I am going in.” Lera said, holding onto the black beam of the Void domain scalpel before slicing open the shielding of the structure Cast and exposing its interiors. Despite the exotic appearance of the defensive Casts, the majority of the compartments within are rather readable.

However, the top layer of the lines seemed…too organized and too empty, and when Lera sliced one of the parts open, there were no Waves flowing within it. The Cast written onto the stones simply broke apart like crackers, and deep down, rougher white lines were drawn onto a strange black material that Wu couldn’t recognize.

“This…” Lera reached her wrist close to it and felt a warmth emitting from the material, “This is the real Cast lines. And…I have never seen anything like this before. Is this…from your world?”

Wu leaned in, and his eyes widened as he caught onto the Cast writing techniques that seemed to have broken every single rule he had learned so far. As one of the more basic methods of Wave usage, Cast making in this world had been practically broken down into a science, just that they lack the actual word for it. Everything was supposed to be well-organized, separated into logical compartments, and each stroke and stripe have its purposes.

But this…Wu would almost describe it as the abstract art cousin of the Cast making rules. No offense to artists, but Wu was always one to over-analyze any pieces of art, and thus always failing to capture the feeling behind it. However, here, he can tell the desperation written into the Cast thorugh the pressure of those strokes.

“No…” Wu said, “This seems like the work of a...other-worldly being, just cause of the way it looked…Could it be a work of the demons from the time of the Third?”

“A remnant of the War of the Third Millennium, and a work of demonic origin…” Lera murmured, “What if the defensive Casts were NOT designed for the purpose written in the Revolutionary Manuscript…”

“Shit.”

Wu and Lera shared a serious look before they both nodded at each other. If whatever’s written on the Revolutionary Manuscript was simply a scheme by the demons in order to manipulate the events on Olympus Prime, leading the humans themselves to activate these defensive Casts before they return and regain control of the entire world, then this would turn out to be far more serious than anyone could have anticipated.

Did Mus know about this? Did he knowingly activate the Manuscript, knowing its of demonic origins? With the outward appearance of what seemed to be from Wu’s world, the Cast was actually made by…demons?

“Too many questions. Too few answers. Damn.” Wu cursed, when Lera climbed further into the tower and started slicing up the internal Casts into individual segments. Despite the Cast writing being more about efficiency and readability in general, the way demons created these Casts has more to do with style and skill.

However, the principles of Wave usage are still the same. Despite the tangled mess in front of them, the broad Cast was still organized by parts layered one on top of another, and Lera quickly discerned the core of the defensive tower with the control mechanisms.

Now, all they really have to do in order to hijack the defensive towers is to replace the control mechanisms while keeping the output of the same signals and destroying any connections to the demonic parts. That was easier said than down, but not impossible.

As Lera worked further inward, she kept slicing open bits and pieces of the structure Cast before handing those pieces down to Wu, who organized them by their supposed functionalities.

Fortunately and understandably, the Casts made by demons still have to run on the Wave, and that meant all the experimental methods Wu had learnt about the Wave can still be applied.

“This was amplification, this was target identification, through a demonic version of scouting eye…” Wu murmured, putting the pieces around one another like a big jigsaw puzzle set, “I see…here’s the communication part…that makes sense.”

“That was the last part.” Lera came down with another handful of warm plaques, “These are the backups.”

“Then…let’s try to put the jigsaw back together.” Wu nodded as Lera ripped out more pages from her book of Casts, “Let's enjoy the holiday activity of putting together our own defensive tower from a dimension of demons~”

For the majority of the components, Lera had pre-made equivalents that were very easy to slot in. And by running some Wave from the inputs and detecting what comes out at the outputs, Wu was able to verify their functionality, at least to a limited extent.

They don’t need to duplicate the entire library of capabilities of the towers, but simply have a single functional mode, which prevents the network of Casts from detecting anything suspicious from this specific defensive Cast.

“There.” Lera stood up and cracked her back as a patch job with glue and paper were stuffed into the interior of the tower. With how efficient humans have made their Casts to be, they were able to save much space within the tower. As the network was reconnected, the Wave started flowing within the circuit once more, and the defensive Cast hummed lightly before remaining stationary.

Then was peace and quiet, and it was as if nothing was out of place at all. Except Wu and Lera had practically replaced all of the internal organs of the defensive Cast without anybody realizing it.

A surgery for a Cast, if you will. And now, this tower is nothing more than a decoration with everything removed.

With great caution and stress, Wu slowly reduced the intensity of his Void Domain shield layer until the output from the replaced communication Cast found its way onto the outside world again, and this specific defensive tower reconnected with the rest of the network.

For the next hour, the group watched anxiously and waited for the rest of the network to take in what had happened, but it was none the wiser. In this scenario, no news is the best news.

“Looks like we’ve done it…” Wu sat back before he rolled over and grabbed onto Lera’s tummy, though that only made her a little self-aware of whether she had gained some weight eating that delicious home-cooking.

“Well done.” The King smiled, “Now, you only got over two hundred defensive towers remaining!”

“I…am not doing that…” Wu grunted, “Lera, my darling, let’s make an SOP.”

“A what?”

“A standard operating procedure.” Wu explained, “A single document with everything anybody will need in order to hijack a defensive tower.”

“Is that…possible?” Joseph asked, his eyes widened, “ANYBODY can do it?”

“So long as they have the right set of Casts, which we should be able to provide as well.” Wu shrugged, “Like I said before, science doesn’t belong to anyone.”

After another week and trips to multiple other defensive towers, the Atlas twins, Wu and Lera, finally had enough trust in their SOP that they were relieved of their current duty.

Then, the work continued as Casters from all over the kingdom worked together to disable and control the defensive Casts. It was hard work, but all of the curious souls learned far more about Casts and Wave abilities than any of them could have imagined.

Obviously, no one quite understood how Void Domain works apart from Wu and Lera, but that’s of no concern to Wu, really. So long as you know how to use and maintain a tool, it won’t really matter if you understood its inner workings or not.

At last, the king of Varous can declare privately the kingdom free from PORA’s threats, for the moment, at least. From the agents in the other kingdoms, it appeared that the modifications to the communication Casts had also performed its duties.

To celebrate their success, the King invited Wu and Lera into the Palace for a dinner party. However, what seemed to be a cheery occasion quickly turned dour, as Joseph came into the dinner table with a scrunched-up paper and a shaking hand.