Chapter 80: Science and Ruthlessness

The members of the special ops team occupied a unique position within the Nightblades. While they technically lacked formal titles, most Nightblades were willing to follow their requests and commands, largely due to Fang's influence. Of course, this also hinged on how reasonable the requests were.

Fortunately, Wang Yu's current requests were far from complicated for them. In a world with magic, their productivity was worlds apart from Earth's medieval standards.

For one thing, salt was never in short supply. As for water, given that they were right by the sewers, a few water magic users could take turns creating water with little effort. It wasn't much of a challenge.

The only difficulty lay in finding magicians proficient in lightning-based spells. Luckily, the Echoing Hearth had several veteran magicians who had just returned from a mission. Though they were aging, their mastery of magic was undeniable.

A few wagons delivered large quantities of salt to be spread across the giant stone vats conjured by Avia and the magicians. Water magic users filled the vats with water while simultaneously redirecting sewer water into them. The rest was left to the veteran magicians.

The seasoned magicians quickly began their work. Maintaining a steady electric current was as straightforward as could be—they needed no bursts of power, prolonged incantations, or worries about enemy attacks.

Metal rods were placed into the concentrated saltwater vats, and the magicians focused their energy on them. Strange purple arcs of lightning emanated from their wands, linking seamlessly to the metal rods and causing their beards and hair to stand on end.

Instantly, the highly concentrated saltwater began to bubble, and a faint yellow-green vapor began to form in the vicinity of the metal rods. With sufficiently concentrated saltwater and a stable source of electricity, chlorine gas could be produced en masse.

"Is this that... chlorine gas you mentioned? Ugh!" Charles leaned in for a closer look, only to immediately regret it. He coughed violently after inhaling a whiff, experiencing the same burning sensation that Wang Yu himself had during middle-school chemistry.

"Wang Yu, I'm dying! What the hell is this stuff?" Charles coughed so hard that a stream of blood suddenly spurted from his mouth, startling him.

"That's just a nosebleed. You were coughing too hard." Wang Yu ignored him, keeping his focus on the rising yellow-green gas above the vats.

Avia and several less experienced Nightblade magicians had positioned themselves behind the vats. Their job was to channel the gas into the sewers, giving the Selwyn rats a painful lesson.

"Oh, you're right." Charles wiped his nose. He'd coughed so violently that he'd burst a blood vessel in his nose, causing blood to enter his mouth before being expelled during his coughing fit—though it did look very much like he'd spat out blood.

"Wang Yu, is this sort of method common among alchemists?" Edward asked, frowning as he observed the yellow-green gas.

He had exposed his skin to a small amount of it earlier and felt a distinct burning sensation, even at relatively low concentration.

If even someone with his physique were affected, how would ordinary soldiers or civilians fare? As the son of a prominent northern engineer, Edward's thoughts extended far beyond those of Charles.

"I wouldn't call myself an alchemist. This is just basic knowledge," Wang Yu replied plainly. He was more like an herbalist, a discipline alchemists generally looked down upon and had excluded from the field of alchemy altogether.

𝗳𝚛𝗲𝕖𝕨𝕖𝗯𝚗𝚘𝕧𝕖𝗹.𝗰𝗼𝕞

As for chlorine gas, this world had some knowledge of it, though the idea of producing it through the electrolysis of saltwater was, to his knowledge, novel. The reason was simple: on Earth, scientists experimenting with chemical substances and electricity had stumbled on it by chance.

In this magical world, such scientific pursuits weren't a priority. Alchemy's foundations lay in magic.

A mix of chemistry and physics were integrated into the process, though only to the extent necessary for specific materials. The focus remained overwhelmingly on the supernatural.

In this world, it was likely that some magician had discovered chlorine gas by chance during a magical experiment, then characterized and noted it down without delving more deeply into it.

The advent of magic stalled scientific progress—after all, when magicians were able to cast Ice Arrow at will, there was little need to invent refrigerators.

Wang Yu wasn't interested in comparing the technological progress of the two worlds. Their trajectories were too different. Besides, magic and fighting spirit could themselves be considered part of the wide domain of "science."

That said, Wang Yu had often considered the potential threats posed by Earth's technological creations—like guns, for instance. These weapons posed a genuine danger to him. No matter how strong his body was, facing steel projectiles was never a trivial matter. Even legendary knights would avoid confrontations with large-caliber kinetic weapons.

In theory, many of Earth's technologies could be replicated in this world. However, Wang Yu's knowledge in this area was shallow at best. He knew nothing about gunpowder, circuitry, or the basics of manufacturing.

For now, his high school to college-level chemistry and mathematics knowledge were his most reliable assets—math, in particular, had even proved useful to Avia.

As for guns, replicating them wasn't entirely out of the question. This world had resources even more convenient than gunpowder: magic. Explosive spells could replace gunpowder entirely. The key to firearms lay in their efficient use of energy—firearms focused it into devastatingly powerful bursts.

A bullet propelled by fire magic would far surpass the destructive potential of a fireball spell. He'd left the task of figuring out how to realize such spells to Avia; if possible, he did want to have magical firearms and ammunition available to him.

But these thoughts about distant possibilities weren't relevant at the moment. Edward's concerns, while valid, were somewhat misplaced. The use of chlorine gas had significant limitations. It was nearly useless in open areas, difficult to produce in large quantities without industrial infrastructure, and generally less practical than a battalion of mages casting large-scale flame spells.

It was only in this specific scenario—a sealed, humid sewer system—that the gas could be truly effective. The enclosed space ensured the chlorine gas would remain concentrated, and the moisture in the air guaranteed that the gas would dissolve and maximize its corrosive properties.

Edward sighed. He still seemed worried. Chlorine gas clearly wasn't difficult to produce, and even had the ability to hurt or even kill even empowered knights. He frowned at the thought of its proliferation.

"Why are you so hesitant now? Normally, you don't think twice before beating me up," Charles teased. "Besides, Wang Yu already said this stuff has limited use. Think about it—mages' curses, wizardry, and necromancers' hordes of undead are all way worse than some gas."

Wang Yu patted Edward on the shoulder as well. There was no need to overthink things. Edward pursed his lips, but nodded in acknowledgment and stopped dwelling on the matter.

"Hey, look at you, coming to terms with things. Why don't you think more about that pretty cat-girl on the corner? I even found out her name for you—Chelsea, a commoner. With your status, she'd fall for you instantly. Ow! Why are you hitting me again?! I'm just trying to help you!"

Wang Yu shook his head and glanced at Edward, who was giving Charles a solid beating. He could understand Edward's concerns to a degree. In many ways, his foresight wasn't wrong. Chlorine gas was, after all, relatively easy to produce, and its destructive potential could well end up significant.

Still, Wang Yu didn't want to overthink things. It was ridiculous to think that he'd bring some monumental change to this world. He was just an ordinary person. Handling the task at hand was enough; worrying about grandiose matters served no purpose.

"All right, get ready—let's start filling it in!" Edward had abandoned Charles and now stood alongside Wang Yu, his expression steady as he prepared for action. A sufficient quantity of chlorine gas had collected above the saltwater pools, blending with the airborne moisture to form a visibly dense yellow-green mist.

Several magicians worked together to manipulate the wind, carefully controlling the toxic gas to keep it concentrated. With the advantage of magic, there was no concern about spillage or dissipation.

Following Wang Yu's command, the salt, water, and electricity generators kept churning. Avia and the other magicians used their wind spells to form a directed current, guiding the yellow-green chlorine gas down into the sewer system.

The sewer, designed without ventilation to prevent foul odors from escaping, was an ideal environment for the gas. The reinforced materials used in its construction further ensured that these toxic fumes would stay contained, while the moist atmosphere of the sewers amplified the corrosive properties of the gas.

Yellow-green fumes rapidly filled the enclosed sewer network, creating a hazy, opaque fog that completely obscured the interior from view.

Charles couldn't help but feel a chill run down his spine. Having inhaled just a trace amount of chlorine earlier, he knew just how unbearable it was. The concentration inside the sewers had to be nothing short of hellish.

Wang Yu, however, was focused intently on the sewer outlet. According to Lubi, the enemies' strongest combatants included an advanced knight and a mysterious "blessed vampire," which he'd never even heard of.

Their team didn't have many heavy hitters in terms of direct combat. Even with his Bloodburn Drive pushing his physical abilities to the threshold of a mid-rank knight, he wasn't truly at that level just yet. The burden of facing powerful enemies fell to Edward, who boasted particularly strong defenses, and a mid-rank knight who was leading a Nightblade squad.

The team's main damage output wouldn't come from melee fighters like them but rather from the magicians—especially the older magicians and the trainee wind magicians assisting Avia. Wang Yu stood poised, ready to intercept any enemies that might charge out of the sewer.

Edward joined him, abandoning his pursuit of Charles. With his shield in one hand and sword in the other, Edward formed a triangular battle formation with Wang Yu and the squad leader, all facing the sewer's exit.

Meanwhile, deep within the sewers, a group of hooded figures stood clustered around a blood-red tumor-like growth attached to the wall.

"Can we really rely on this so-called blessed vampire?"

"Our family guarantees its efficacy," snapped one of the hooded figures standing closest to the tumor. "This is a result of the Selwyn ritual you provided, derived from that creature you call the ‘Font of Life.' Creating this thing cost us no small amount of effort. The least you could do is extend us some trust."

"Trust? From a family that betrayed its own kingdom? Don't you think that's a bit ironic?"

"Damn it! Are you here to mock me or cooperate?! I'm doing this to help you out!" The hooded figure bristled with anger, his voice rising.

"Fine, fine. But you'd better ensure it works. Selwyn will reward you well for success."

"Let's hope so," the first figure muttered coldly, casting a wary glance at the blood-red tumor pulsing faintly on the wall.

He couldn't suppress a shiver of fear as he thought of the gray, worm-like creatures that had killed and replaced the city guards who ventured into the sewers.

Whatever this blessed vampire was, its nature was deeply unsettling. As for the "Font of Life," that grotesque, colossal being worshipped by the Selwyn people—that thing was nothing short of terrifying.

"Oh, by the way," one of the Selwyn figures chimed in, his tone suddenly cheerful. "You shouldn't refer to the Font of Life as a ‘monster.' That's blasphemous. It's a great deity, after all. Mind your words—wait, what is that?"

The hooded Selwynian trailed off as he noticed yellow-green fumes beginning to roll in. The gas advanced rapidly, billowing from all sides.

He didn't know what the strange substance was, but an ominous feeling settled over him. Instinctively, he wanted to avoid it, but there was no escape. By the time he noticed it, he had already inhaled a low concentration of chlorine gas. A burning sensation seared through his nose and throat, triggering a burst of shock and fury.

"Hey, you from Aleisterre! What's going on with this sewer system?!" The Selwynian figure turned back to voice his anger—only to freeze, realizing something was horribly wrong.

The person who had been standing near the blood-red tumor was no longer whole. He had been split into two. His lower half lay on the ground, convulsing and spurting blood, while his upper body was held in a blood-soaked, crimson hand. The hand dragged the lifeless torso into the tumor.

His dilated pupils quivered in horror as they met a pair of malevolent crimson eyes staring back at him.