An Invitation in the Dark
Heading for the racetrack where the parasite had been spotted together with my superior, it didn't take us long to find our target.
Watching from cover, the creature—disguised as a human woman named Lee Ji-yoon—held a betting slip in one hand, carefully studying the horses in the paddock just before the race.
Its immaculate appearance was ill-suited to the place, and amid the crowds of middle-aged men and women, her beauty stood out—refined, intellectual, and impossible not to notice.
"Oh, for god's sake… I've seen a lot, but this is the first time I've come across a parasite bastard coming to the racetrack to make money."
Celine—the woman who was my superior, and who only weeks ago had killed a parasite masquerading as a director at Seosan Life Insurance—burst into a disbelieving laugh as she studied the creature.
With her long black hair and dark eyes, she looked close to East Asian, but mixed into her features was the blood of some unidentifiable Western lineage, which made her, much like the parasite, something of an oddity here.
She wore plainclothes for the tail, and the foxlike look on her face was worn at all times like a mask.
While her looks might divide opinion, hardly anyone would dispute that she was beautiful.
"What do you want to do?"
When I asked, in an even voice, how she meant to proceed, she chewed her gum contemplatively, lost in thought.
It was confirmed now—the creature was a parasite.
The question was how to respond according to its rank.
Everything suggested a Rook, but establishing that for certain was the very reason we were here.
"…No idea."
That was the conclusion reached by Celine, herself an A-rank, her eyes narrowed to slits as she bored her gaze into the parasite.
When even she—just one tier above me—couldn't pin down the monster's rank, a creeping sense of crisis settled over me.
"Should we request backup from headquarters?"
At my question, Celine spat her gum neatly into a wastebasket and smacked her lips.
From the look of her, she wanted nothing more than for the two of us to charge in and take it down ourselves, but she wasn't fool enough to rush an enemy of unknown rank.
"Let's fire off a request first—shit, it made us."
The parasite suddenly began moving toward somewhere else.
It could simply have been leaving after finishing its business, but something about it didn't feel that way.
"We follow."
"But—"
"What, you want to lose it? It seems to have noticed us. If we let it slip away here, it'll vanish completely among the humans, and finding it again won't be easy."
"…Understood."
It was reckless, but if the goal was simply not to lose the parasite and to kill it, her reasoning held.
"Fire the backup request, and keep them updated on our location in real time."
"Yes."
"Let's move."
In stark contrast to her coarse mouth, the ever-smiling corners of Celine's lips were climbing higher and higher.
I didn't need to be told that the excitement came from the prospect of killing the parasite.
The agents who took up the hunt for parasites came from every kind of background, driven by every kind of reason—but for most of them, it was vengeance.
A cherished person slaughtered by a parasite, and a motive for revenge that was unoriginal, perhaps, but absolutely certain.
Celine was no different—yet she was also a little special.
Her mother had been eaten and replaced by a parasite, and Celine had been raised in its care.
By all accounts, it had played the role of mother faithfully, until one day—whether from some change of heart or none at all—it killed her father and her siblings, every last one, but never laid a hand on Celine herself.
No one knew why. Whatever the reason, it was more than enough to make her an agent bent on exterminating parasites.
"Look at this bastard. It's steering us somewhere with no people around."
Now tailing her through the subway—not a tail in anything but name—Celine laughed like this was the most fun she'd had in weeks.
There was an unspoken taboo shared by both parasites and the organization.
Neither side wanted their existence exposed to the world.
If humanity learned what the parasites truly were, feeding would become infinitely harder for them—and the parasites, in turn, had no desire to breed panic across society.
Perhaps the creature's movement was rooted in that same silent rule.
We trailed it toward a place with few people around, and before I knew it, we were standing before a building under construction, drenched in deep darkness.
I tilted my head back at the flagrant, almost insulting sense of wrongness—and there, on one of the wide-open apartment floors, the parasite was looking down at us with dead, expressionless eyes.
"Ah-ha… so it wants a fight."
"We should wait until backup arrives."
When Celine reached into her coat to pull out the drug developed exclusively for her body, I spoke up urgently.
That drug, exploiting her unusual constitution, might let her hold her own against a Rook for a while—but it wouldn't put one down.
"…Where are they?"
"Ten minutes out."
"Composition?"
"We're assuming at least a Rook. Four A-ranks, plus three B-ranks in support. That's every available agent currently on standby at the Korean branch, assembled."
"In ten minutes I could at least introduce myself, couldn't I?"
My calm brow furrowed on its own.
I understood her hostility toward parasites, but this was reckless beyond all reason.
The enemy might be a Rook—and no matter how brief the engagement, taking one on as a pair meant a high probability of death.
"Relax, it's a joke. I'm not that stupid."
Celine slipped the drug back into her coat and, to make a show of it, spread her hands wide with a mischievous grin.
I shot her a mildly resentful glance, then kept watch on the parasite's movements as we waited for the requested team—until a thought struck me, and I asked it aloud.
"…What if it's… a trap?"
An ordinary parasite would have gone to ground the instant it was discovered, but there was no sign of that here. Instead, as if daring us to attack, it sat motionless in a deserted place.
Or… could it be that, as a Rook, it believed it could take all of us at once?
Come to think of it, this would be my first time facing a Rook.
A brain that had never harbored anything beyond rational calculation began, slowly, to seep with unease.
"Could be."
Celine had evidently reached the same thought—she pulled gum from her coat and started chewing again, leaning against the wall and bouncing one leg impatiently as she waited for reinforcements.
She had worked herself up to a state of feverish excitement, and I could see it plainly—the effort it was taking her to hold herself back.
"All the better if it is a trap, then. We can kill them all in one spot, can't we?"
I made no reply to that easygoing remark and checked my wristwatch.
The planned ten minutes had come and gone long ago.
I was about to contact headquarters again to trace their location when—
"…I can't wait any longer."
"Wait a—"
"Shut it."
Celine pulled the drug from her coat, swallowed it, and began climbing the floors.
Another headache washed over me at her heedlessness—I'd lost count of how many times— but I had no choice except to follow her.
Had she been an ordinary subordinate, I would never have joined such a reckless move, but she had saved my life on more than one occasion in the past, and so I had no option but to follow.
She hadn't changed into her combat suit—she was going in bare-handed, the only thing in her grip that peculiar revolver that only she could use.
The truth was, from the Knight rank upward, combat suits were useless.
If the goal were to stop the parasites' tentacles—the ones that tore through human flesh and muscle like paper—then yes, means of blocking them did exist.
But blocking them meant, no matter what you wore or carried, hauling around an enormous weight.
Those of us reinforced through procedures and drugs could carry or wear such things, but the movement restrictions that came with them were unavoidable.
Unfortunately, modern technology had yet to produce any means of deflecting a monster's tentacles while shedding that weight entirely.
And so some instead chose to fight on the premise of simply never being hit—making the body as light as possible.
Celine was one of them.
Gulp.
She swallowed the pill made for her special constitution—far beyond the lethal dose her creator had set for it.
Every fiber of me wanted to stop her from abusing her body like this, but what was already inside her couldn't be taken back.
Letting out a quiet sigh, I installed the special sound-dampening machines around the building to seal off noise.
At this level, hardly any sound would leak outside.
I transmitted the brief message to headquarters and, without waiting for a reply, checked my own equipment.
The black protective suit, trimmed down to cover only the vital points, might as well have been paper for all it would stop a Rook's attacks.
I wore it anyway—as a matter of psychological reassurance and the barest minimum of defense.
My weapons: a submachine gun and a sidearm loaded with rounds designed to counter the parasites' rapid regeneration, along with an assortment of grenades prepared for different situations.
For a B-rank agent as unremarkable as myself, this standard loadout was about the extent of what I could arm myself with.
At the same time, the gun—the one form of ranged attack that gave humanity its single advantage in a fight against parasites—was also our greatest weapon.
I knew what we were doing was reckless and irrational. But having chosen to follow Celine, I hesitated no longer.
Grrrk.
Concentrating my will, I awakened the parasite cells injected into my body through the procedure—and grotesque blue veins began to rise across every part of me.
Celine was the same, only worse; the drug had pushed her awakening even higher, and the veins had climbed all the way up her face.
In places, something was even beginning to protrude from her skin—rare for her—and on closer look, it resembled tentacles.
"Two of us, is it?"
Where Celine openly revealed herself, I concealed my body behind a pillar in the darkness—and moonlight streaming through the gutted building lit the parasite up.
Having stolen the appearance of the human woman Lee Ji-yoon, it stood alone and unguarded on the wide-open apartment floor, its pristine suit and intellectual beauty set off against the night sky on all sides.
"Ah, our teammates will be here soon. We just came to say hello first. By the way… you're not calling any friends of your own? Isn't that why you lured us here?"
Even at the height of her excitement, Celine hadn't entirely lost her reason—she shrugged and asked guilelessly what it was thinking.
"Friends? There are none of those. I am alone here. …Did you think this might be a trap? You needn't worry about such things, so rest assured."
That complacent answer struck a nerve deep in Celine.
The foxlike corners of her mouth stretched wider and wider.
"Alone? Hee hee~ you absolute fucking bitch… a Rook, talking all high and—"
Crack.
Mid-sentence, Celine yanked the trigger of her revolver in an ambush.
A shot into the enemy's blind side—a specialized round, several times faster than any standard slug, blazing toward the parasite wreathed in electric current.