Confirming the dead mouse had completely vanished into the briefcase's extradimensional space.

Before Su Jin could even catch his breath, a wave of sheer ecstasy hit him!

A fresh line of text had already projected itself across his vision.

[Extraction successful. Equivalent item compensation issued.]

Incredible!

The company's methods might be brutally crude, but their operational efficiency was off the charts!

Riding a sudden high, Su Jin hurriedly shoved his hand back into the leather bag.

After a brief fumble in the dark interior, his fingers closed around a black cardboard box.

Staring at the sleek, compact box in his hand, a sudden wave of apprehension washed over him.

Aside from the starter kit, this was his first legitimate transaction with the company.

One item was a mask that provided a HUD and seamless universal translation.

Another was a briefcase boasting extradimensional storage.

The third was a firearm that supposedly required no reloads, though he had yet to test it.

Given that track record, whatever was in this box was absolutely not Mortal Grade!

Taking a deep, steadying breath, Su Jin built up a sense of grand ceremony and popped the lid of the black box.

As the flaps parted, a dull silver sheen caught the light.

It was a perfectly curved metal object, smooth, teardrop-shaped, and distinctively resembling an adult novelty toy.

A very familiar, deeply bizarre shape.

The triumphant smirk on Su Jin's face slowly slid off.

Trembling, he reached in, pinched the metal object between his fingers, and lifted it into the light.

After staring at it for exactly two seconds, his psychological defenses shattered. He violently hurled the box at the floor!

"What! The! Fuck!"

"Is this a fucking butt plug?!!!"

Su Jin stood there, gripping the heavy steel plug, trembling with absolute, icy rage.

Motherfucker!

You don't play with a man's dignity like this! This was a sick insult!

He was already living on the ragged edge of a panic attack.

The world was ending, and his corporate sponsor mailed him a butt plug. What, did they want him to cork himself so his bodily fluids wouldn't leak out when a zombie chewed his throat out?

After spitting a venomous string of curses at the ceiling, the adrenaline finally burned off.

Staring down at the "adult toy" in his hand, a profound sense of desolation settled over him.

He was shackled to a psychotic, unreliable company that viewed his life as a complete joke!

If he hadn't gone drinking with that damn client in his past life, he never would have ended up in this mess...

Just as he was drowning in a puddle of his own self-pity, something on the floor caught his eye.

A small, folded card had spilled out of the discarded black box. An instruction manual?

Wait, maybe this was a misunderstanding. The company was a transcendent, multiverse-spanning entity. There had to be a logical explanation!

Desperate for a reprieve, Su Jin snatched up the card.

[Emergency Suppository: Contains highly concentrated emergency healing serum. Automatically deploys payload upon detecting a critical drop in core anal temperature. Rated for multiple uses until payload is depleted. Note: A severe burning sensation is normal; please do not panic.]

[Special Warning: If the user must venture into lethal danger, please insert into the correct anatomical position in advance to avoid missing the critical deployment window. Do not forcibly dismantle the casing, as the serum degrades instantly upon oxygen exposure. For suppository use only. Oral ingestion carries a 99% risk of fatal toxicity.]

"It's still a fucking butt plug!!!"

Veins bulging in his forehead, Su Jin slammed the manual into the floorboards.

'Insert into the correct anatomical position in advance'... who the hell was going to waddle through the apocalypse clenching this thing?!

He would rather bleed out in the street than use this degrading piece of hardware to cling to life!

It took him ten full minutes of heavy breathing to calm down. Coldly pragmatic once more, he found a length of paracord, tied it through the flared base of the Emergency Suppository, and hooked it to his tactical belt.

He would absolutely never use it himself. But considering Qingdai was a civilian and highly vulnerable, he’d keep it on hand for her, just in case.

...

The biological trials had to continue. Forcing his mind back to the task, Su Jin extracted two fresh mice for the infection protocol.

The subject currently locked in the hamster wheel had fully turned. It was relentlessly throwing itself against the plastic barrier, trying to launch a suicide charge at Su Jin.

Unfortunately for the rat, it was trapped in a spinning wheel, forcing it into an endless, agonizing sprint.

Crouching by the cage for a long time, Su Jin finally picked up his pen and began logging data.

The particulate matter in the Gray Rain was unequivocally the mutagen, and the speed of zombification directly correlated with the volume of exposure.

As of now, he could only conclude the transmission rate was catastrophically high.

With his crude, amateur setup and limited supply of test subjects, calculating an exact mathematical probability of infection was impossible.

Post-infection, the subject's fine motor skills severely degraded. Its limbs moved with mechanical stiffness, and its top speed plummeted. However, it exhibited zero signs of fatigue and a complete absence of pain receptors...

After scribbling down the baseline metrics, Su Jin snapped a fresh pair of AA batteries into the gutted 4WD toy car.

The tiny motor shrieked to life, spinning the hamster wheel at a punishing RPM.

The mutated mouse couldn't keep pace. It tumbled violently inside the plastic drum, yet every time it flipped, it viciously snapped its jaws, desperately trying to reorient and attack the glass.

Twenty minutes later, the batteries died. Su Jin swapped in a fresh pair and hit the switch again.

He burned through five consecutive sets of batteries before finally cutting the power and manually spinning the wheel himself.

Staring at the tireless creature, Su Jin couldn't mask the grim disappointment in his eyes.

The conclusion was a nightmare... The mutated mouse had suffered zero stamina drain. If anything, its muscle fibers seemed to be actively adapting to the abuse, growing marginally stronger.

Another hour ticked by.

He ran the subject through a gauntlet of horrors: suffocation, immolation, drowning, and physical trauma. By the end, Su Jin's heart felt like a lead weight.

It couldn't be suffocated. It couldn't be drowned. Even after he torched it until its flesh was completely carbonized, the charred husk still twitched.

The pathogen granted terrifying survivability. The only reliable method of rapid termination was severe trauma to the central torso. Even decapitation didn't yield an instant kill.

He didn't know enough about rodent anatomy to pinpoint the exact organ, but he assumed he was hitting the heart.

The only metrics left untested were the maximum lifespan of the host and its ability to transmit the virus to its own species.

But Su Jin was physically and psychologically tapped out.

He dropped the wire cage into a heavy glass aquarium he'd bought earlier, slapped a wooden board over the top, weighed it down, and dragged himself into the bedroom.

...

In the pitch black of the room, the second radio—the one locked to the AM band—burst into static.

Su Jin forced his heavy eyelids open and lunged for the dial.

FM was local. It had a short range and was mostly used for civilian entertainment. AM, however, bounced off the ionosphere, giving it massive range and interference resistance. It was the absolute gold standard for national emergency broadcasts.

Even though this wasn't Earth, the physics of the universe and technological progression were identical. He had researched this exact scenario.

If the AM band was broadcasting, it meant the central government had recognized the threat and was mobilizing the nation.

After a few frantic tweaks of the dial, the signal locked in.

Hiss—crackle—

"...This is a Priority One broadcast from the National Disaster Emergency Command Center. All citizens are ordered to pay immediate and strict attention—"

"As of 1300 hours today, the majority of the national territory has been subjected to an unidentified meteorological event. This anomalous rainfall possesses severe biological hazard properties. Exposure may trigger irreversible physiological damage via dermal contact, inhalation, or ingestion."

"We have confirmed that the sudden outbreaks of mass violence and psychotic behavior across multiple municipalities are directly linked to exposure to this precipitation..."

"By order of the central government, all citizens are to execute the following directives immediately: One. Under no circumstances are you to make direct contact with any form of rainwater. Two. Consume and utilize only factory-sealed bottled water or strictly quarantined reservoirs. Three. Immediately seal all doors, windows, ventilation shafts, and drainage pipes to prevent external moisture intrusion."

"These directives carry the weight of martial law and are effective immediately. Any individual found in violation will be charged with endangering public security... Further updates will be broadcast across all radio and digital networks."

The static returned, but Su Jin felt a massive weight lift off his chest. He let out a long, ragged exhale.

Thank God... The state's machinery of violence was finally spinning up!

The government clearly understood the apocalyptic severity of the Gray Rain. They hadn't even bothered with the standard "remain calm, it's just a rumor" PR spin. They went straight to lockdown.