A single child left alone in the grand parlor.

The trainee agents who had survived extreme conditioning were treated to a lavish feast—before being placed on the final test platform.

“Using children as a tactic in war is nothing new. Sending them into enemy lines first to lower a soldier’s guard has existed for ages. When that happens, will you be able to pull the trigger without hesitation, even with a child in your scope?”

“......”

“If that child crosses the line, hundreds, thousands of your comrades will die. And yet, will you refuse to shoot just to protect your conscience? What you must uphold is not petty morality, but patriotism and loyalty.”

“......”

“Compassion is a burden to people like you.”

Sonia stood before the trainee agents, facing their moral dilemma. Some bowed their heads and trembled. Some wept. Some gave up and stormed out of the room. Others lit cigarettes with shaking hands.

Even so, there were those who gritted their lips and raised their rifles. The moment they clicked the chambers into place, Sonia leapt onto all fours and scrambled across the furniture, whistling. She hoped Kiya, dragged into the next room, would hear her signal.

A trainee, startled by Sonia’s sudden movement, fired. Bang, bang—! A chandelier shattered and glass exploded. Sonia clutched the curtain and hurled herself through the window.

“Sonia―!”

At that exact moment, Kiya also swung out the adjacent window, clinging to the curtain. Like the perfect pair they were, they seized each other’s arms and climbed up to the roof.

She didn’t know how many children had died, but until Winter Castle exploded, they had been the longest-surviving pair.

Sonia and Kiya.

Children who grew more vicious together. In the darkened manor with no light, their aggression only escalated.

We were pitiful, savage things raised for a purpose. Little beasts who ran on all fours and flew without fear.

Sonia crouched like a mouse, a blade gritted between her teeth, eyes glinting.

And somehow—she always survived.

“Don’t touch your head carelessly.”

At some point, her hair had been shaved bald, and she’d been made to wear a heavy mask over her skull. When the metal touched her forehead, it sent sharp jolts through her nerves, and the weight crushed her neck until it bent low. Her head throbbed day and night.

From then on, her memories began breaking apart.

Kiya’s cheerful chatter grew sparse. Hunger didn’t come even when they didn’t eat. Sometimes, the back of her head itched so badly that when she slapped the mask, the manor staff would scold her harshly.

“Hey! That’ll make the wound worse! You’re not to touch it until it heals!”

She couldn’t remember getting hurt—but they said there was a wound at the back of her head. These days, she’d wake up to find days missing from memory. But she didn’t think much of it.

The full-face mask, pressing tightly around her skull, became unbearable during the stretches when no trainee agents came. They slept like corpses and suffered splitting headaches.

“Sonia, Sonia... my head hurts...”

“The back of mine itches like hell...”

Behind their masks’ eyeholes, they stared at each other’s teary eyes. To bear the heavy headgear, they rested their foreheads together whenever they could, bracing themselves with each other’s bodies.

Whenever the masks came off and they were led back to the outbuilding, their bodies felt strangely light. They saw better, heard better. Even without eating much, they felt full of strength.

If they ran into someone hot-tempered or cold-blooded, they’d return with sunken cheeks and bruises—but at least, they didn’t die.

After the headaches started, they became crueler. They spilled more blood. They survived in tatters.

But whenever they saw another sibling carried out dead, their eyes would fill with quiet envy.

Maybe... it’s easier for them now. Their suffering had ended. Their pain was over. Each time those thoughts surfaced, Kiya clung to her like a ghost.

“Sonia, Sonia. I hate that look in your eyes.”

“What look?”

“You want to die and be carried out like them?”

“......”

“You don’t want to stay here with me?”

“I don’t know.”

“You can’t die, Sonia. You can’t leave me.”

“...Okay.”

“Promise me. Sonia, promise.”

Sonia stared blankly at the dazzling snowfield. The siblings being carried out were so small. She reached out her pinky—limp, unsure—and a hand, hard as iron, linked with hers.

The door to the outbuilding creaked shut, and that paradisiacal landscape slowly drowned in darkness. Then the coffin opened, and a sudden flood of light blinded her.

***

“Seoryeong, get a grip—Han Seoryeong!”

No, that’s not my name...!

Her forgotten pinky throbbed as if it had been torn off. Sonia slapped away the strong hand gripping her body. Ligai’s prosthetic eye case rolled inside the coffin as she twisted her body with all her strength.

“Han Seoryeong!”

No, I’m not Han Seoryeong...!

We were mice of Winter Castle. We were the final gate. We were nothing. The name we were called—was Sonia. Kiya and Sonia. The last rats who survived Winter Castle. The strongest children.

“Ugh, ugh...”

Her body was still paralyzed; all she could do was groan. The pain in her skull felt like bricks pounding into her forehead. The flood of memories that had exploded through her head surged like they were about to burst through her veins. The pain made it impossible to even open her eyes.

My... my name is Sonia. I was the rat of Winter Castle. I was the final gate...―

“Hold still... This is an antidote injection.”

A man snapped the cap off a syringe with his teeth and plunged it into her forearm. She felt the sting of cold fluid flowing into her bloodstream. Fragmented images flashed across her vision.

Each memory tore into her like a festering wound. So that’s how I lived... That’s how we survived... Not a single moment of it was something to be proud of.

“Ju... Juusa...”

“Yes, it’s an injection. The paralysis will wear off soon. You had trouble breathing in that coffin? I came as fast as I could. Were you very scared?”

The man let out a bitter sigh and wiped her sweat-drenched forehead. When his dry lips brushed the edge of her eyebrow, Sonia recoiled sharply and turned her head.

“No, ugh...!”

They gave her injections back then too.

This is a magic spell just for you, the man had said in a trembling voice that still knotted through her brain.

I’ll cast it so you can never undo it.

Blood vessels bulged with the mental overload.

“From this moment on, you’ll forget all the unhappy memories.”

Whose voice was that? 𝒻𝓇𝑒𝘦𝘸𝑒𝒷𝓃ℴ𝑣𝘦𝑙.𝒸ℴ𝘮

“Forget every unhappy memory.”

It was the voice that had stretched a net tight across her brain. Before leaving Winter Castle, they had been injected too. Who had been the one administering injections to the children of Sakhalin?

Curly-haired, dark-eyed man. Black hair, black eyes. A fellow Asian who spoke their language. His name was... that man’s name was... Ri...

“Your scary memories will never come back. I’ll chase them far away, right now. Okay—look straight into my eyes. I’ll count down. When I reach one, the lock will close.”

“......”

“This pattern in my eye is the key to your memory. But don’t worry. As time passes, you won’t be able to meet me again—or even look me in the eyes. I’ll make sure of it.”

It had all happened in a rush. But unlike the man trembling with his clenched jaw, strings carried the soft melody of a string instrument through the wind.

Winter Castle had been loud that day. It was buzzing with noise. Petals of light had rained from the sky.

“If someone asks about your childhood, just remember the happiest part. From now on, you’ll live not as a child from Sakhalin—but just a normal child. I’m sorry I didn’t recognize you, my daughter... From now on, I hope your life is filled only with love.”

Ten, nine, eight, seven, six... Five. You leave the castle of monsters. Four. You feel light and refreshed. Three. New energy rises within you. Two. Your mind becomes clear. One. You close your eyes slowly... and open them.

She gazed up at the sky with her dulled mind. Crimson flames roared skyward. Her head, just pulled from a deep dark hole, could only stare blankly.

Winter Castle had been destroyed. But what happened to the others? Did the rest of the siblings all burn and die?

But the injection had been «N.o.v.e.l.i.g.h.t» given to all of them. Kiya had heard the memory-banishing spell too.

“We don’t have time to waste. We need to get out now. Agent Han Seoryeong, can you hear me? Focus. Look at me. Seoryeong, do you hear my voice?”

Sonia stared at the man gently tapping her cheek.

“――”

And the moment she recognized his face, she broke into sobs. Lee Wooshin’s expression hardened into a pale blue as he moved to hug her—but she shoved him away with all the strength she had. His eyes tightened like he’d been punched by the rejection.

When she awoke from her long winter sleep, she was already in South Korea.

Sonia began her second life under the name “Han Seoryeong.” But from a young age, she displayed behavioral issues and underwent regular counseling.

After entering an age-appropriate school class, she took up gymnastics that bored her to death.

Compared to the inhumane circus in Sakhalin, competitive gymnastics was refined—but dull to the point of madness.

She fell in love with an ordinary office worker. She had the marriage she’d dreamed of, and lived a truly warm newlywed life.

Then her husband disappeared. They said he’d been a black agent with the NIS.

So I...

I went looking for him...

“Don’t you dare touch me, you filthy agent bastard...!”

Lee Wooshin’s pupils trembled mercilessly.