When the game of an advanced civilization invaded and the apocalypse broke out, the world's population was cut in half in under ten years. The land humans could inhabit kept shrinking.
To preserve human civilization, humanity circled off the most habitable surviving ground and gathered every survivor within it, naming it — the Homeland.
Purifiers held a special status; earning the credentials required passing examination after examination.
The moment Xi Yan stepped into the Homeland's core institution, a blindfold was forced over his eyes. Jiang Chen murmured “don't be nervous” by his ear, and then an unfamiliar presence appeared at his side.
“I will take you in from here.” The man was sparing with words, gripping his arm and marching him forward.
After about five minutes, a voice said, “You may remove the blindfold” — and when it sounded, no one was beside him. He stood alone in a sealed chamber.
Everything within sight was coated in a layer of white insulating substance. Before him stood three glass doors, behind each locked an ordinary person with a different contamination level.
“Purify them, and the purifier credentials are yours.” The same voice as before, sourceless, rang through the chamber three times.
Then, on each door, a round button surfaced, engraved with the character for “press.”
Xi Yan never gambled on the untested. Before entering, he poked Bubble out. “What can this purification ability actually do?”
[Short of those fully assimilated, any contamination level can be brought down to the safe range. One hundred percent.]
Xi Yan pressed the button on the first door. Its outer ring lit up green, then dissolved into pinpoints of light that scattered into the air.
Inside was a middle-aged man, who burst out the moment the door opened: “Hello — are you the new purifier?”
“Don't be nervous. My contamination level is currently forty-seven percent. For us ordinary folk, under thirty is the normal range, but any drop of ten percent counts as a pass. Before you, I had the honor of meeting three purifiers.”
The man raised both hands. “By the way, does your purification talent need any special form? I'll cooperate however I can — I won't hurt you.”
“No need.” At Xi Yan's thought, a pale-blue halo spread from his body onto the man before him.
The needle on the recording device trembled, then spun at full speed. In under three seconds, the man's contamination level plunged from forty-seven percent to zero, and the device went still.
Xi Yan didn't linger. He opened the second glass door.
The man inside was curled in a corner — not speaking, not lifting his head, only hugging himself and shaking, moaning now and then, “I don't want to die.”
His contamination level had hit seventy-six percent. His hair, dry and yellowed like dead grass, hung in sparse strands.
For someone with an awakened ability, anything under eighty percent was manageable. For an ordinary person it was another world entirely: at this level, death was at hand. They never survived long enough to be assimilated — past eighty percent, most had only one road left.
This door's requirement: bring it below seventy percent, and slow the dying.
Xi Yan stepped closer and released the purification light as before.
At one minute, the trembling in the corner stopped.
At two minutes, the man's head turned toward the instrument that never stopped recording his body's data.
At three minutes, his eyes flew wide — he saw, with perfect clarity, a number that could not possibly exist! When he turned again, he caught only a glimpse of Xi Yan's back; he never even learned who had saved him.
But he knew that figure must have gone to the third door. He scrambled out on all fours and collapsed at the threshold.
The contamination was gone, but the damage it had done remained.
Xi Yan noticed none of this; he was already standing before the third man.
The third was bound to a black pillar, deep in madness — horns sprouting from his skull, limbs fully bestial; only the face still showed anything human.
His awakening had failed, and his contamination level had climbed far past the limit an ordinary person could endure.
According to the report, within three hours at the latest he would become one of the myriad races outright — whereupon the black pillar's energy would blast him to dust.
Xi Yan set down the report, pressed several switches on the console as instructed, and stood before the man — contamination closing on one hundred percent — through wave after wave of shrieking.
He raised his right hand. Blue purification light bloomed from his palm, widening until it swallowed the man whole.
The shrieking faded lower and lower.
Twenty minutes later, every trace of beast transformation had vanished, leaving only a body ravaged almost past recognition by the contamination.
Xi Yan frowned. Before he could speak, Bubble's voice came through: [No. This is only a purification ability. It is not omnipotent. Healing is a healer's work.]
“Fine. ...Wait, no — weren't we promised someone would come fetch me when the purification was done? Where is everybody?”
The words had barely landed when something like an alarm detonated overhead. Every instrument around him began shrieking beeps at once.
Xi Yan looked around wildly and dropped into a crouch, arms over his head: “What now? The myriad races are attacking? I'm a purifier, for heaven's sake — why is no one protecting me? Little Bubble, let's make a deal: when the mission settles, count this one as a success, okay? I was working with the utmost diligence! It all happened too suddenly — none of this is on me!”
[Participant 95627, this is not like the alarms in the real world.]
“Meaning what?”
[The recommendation here is that you stand up first.]
Stand up?
Xi Yan didn't get it, but that had never stopped him from complying.
The moment he rose, a red-haired elder with a red-splotched face and a red horn jutting from his forehead darted out in front of him, startling him three steps back.
“Holy—! What is that thing?!”
[That is the supreme commander of the Homeland.]
The elder extended a right hand, the wrinkles at his eye corners bunching together: “I am Cheng Du, supreme commander of the Homeland. I've come chiefly to hear how you managed to purify all three of them down to zero.”
Xi Yan had barely extended his hand when a white light burst before his eyes. Two seconds later, the glare was gone, replaced by an office from the old world.
“Sit. Make yourself at home.” Cheng Du pushed a cup of tea toward him.
Xi Yan eyed the pale-blue tea, casually purified the contamination out of it, raised the cup, and downed it in one go. The warm tea slid down his throat into his stomach, blooming with sweetness — sweet but not cloying, unlike any tea he'd ever had.
Cheng Du watched the purification, and the reaction afterward — and asked: “Well?”
“A little sweet. Tastes good.”
Cheng Du took a sip of his own, unhurried. “This tea is bitter.”
“Impossible.” Xi Yan sprinkled a little purification light into Cheng Du's cup. “Try again.”
“Indeed. Sweet on the finish.” Cheng Du's tone turned on a coin; the amusement drained from his eyes. “Would you care to explain how you did it?”
Xi Yan answered straight away: “My purification ability is special. I can bring certain people down to zero — but those already contaminated in the womb can never be fully cured. Only those who were clean before birth qualify.”
“Evidently, those three happened to meet the requirement.”
Cheng Du said nothing at all, only stared at Xi Yan — until his scalp prickled.
“Is there a problem? You may not understand. This is the world of geniuses.”
The smile returned to Cheng Du's face, and an identity card materialized in his hand. He pushed it in front of Xi Yan: “Congratulations on passing the assessment. You are now officially a purifier of the Homeland, engaged in the greatest endeavor of humankind.”
“Thank you.” Xi Yan took the identity card floating before him. It felt cool and warm at once — nothing like his old employee badge.
“You're fond of that boy Jiang Chen, aren't you? Relax — just making conversation.”
The topic had turned too fast, but Xi Yan answered honestly: “He's my boyfriend. We're dating.”
“He's waiting for you at the door right now. You may go, child.”
A strength that could only be called gentle pushed Xi Yan out the door — a force like wind, bearing him up, yet permitting no pause.
When he stepped through, the force vanished.
He glanced back: the strangely featured elder still sat on the redwood sofa, a smile still on his face, until the door swung fully shut.
Behind it, every trace of smiling left Cheng Du's face, his brows knotting into a tight crease.