Actions

Work Header

mastermind

Summary:

Where their Kingdoms had been at war for decades, but when Seongje becomes the King it all changes. One single bad decision from Eunjang's Queen dooms everything for them, and all they have left is to surrender.

— SJSE WEEK DAY 1 ; forbidden love.

Chapter 1

Notes:

(See the end of the chapter for notes.)

Chapter Text

 

“No one wanted to play with me as a little kid
So I've been scheming like a criminal ever since
To make them love me and make it seem effortless.”

 


 

 

The war room in the palace of Suyeong was cold, the air thick with the smell of fear and burnt cedar. Prince Yeon Sieun stood before the vast map carved into the obsidian table, his finger resting on a narrow mountain pass marked in fading gold leaf.

“General Choi is overextended here,” he said. His voice was quiet, but it cut through the heavy silence. He did not look at the weathered Alpha commanders seated around the table; he spoke to the map itself. “Scout reports from the eastern ridges show repeated, probing incursions by General Kang’s forward units. It’s not a feint. It’s the prelude to an encirclement. If we do not reinforce or order a full retreat within two days, we will lose the entire eastern legion.”

A low scoff came from his left. General Park, his face a landscape of old scars, shook his head, the gesture dripping with disdain. “An encirclement? Through those cliffs? It’s suicide. The Silverbark Pass is impregnable. We hold the high ground. I will not order a retreat on the word of a boy who reads more books than battle reports.”

Sieun’s mother, Queen Yoona, watched from her elevated seat of jet-black stone. Her expression was impassive, carved from the same material as her throne. “The Prince’s… assessment is noted,” she said, her tone leaving no room for debate. “But we will trust the instincts of our commanders in the field. Hold the pass.”

Sieun’s jaw tightened, a minute twitch that only one person in the room noticed. Ahn Suho, standing guard by the arched doorway, saw the flicker of frustrated comprehension in his prince’s eyes before it was extinguished, replaced by blank acceptance.

“As you wish,” Sieun replied, the words neutral and chilled. He inclined his head, the motion perfunctory, and turned. The soft grey silk of his robes whispered against the stone floor as he left the chamber. Suho fell into step behind him, a silent, protective shadow.

The misty, pine-scented corridors of Suyeong were a relief after the stifling council room. “They never listen,” Suho muttered, the words a familiar, heated whisper against the damp stone.

“They listen,” Sieun corrected softly, his gaze distant, fixed on some internal calculation. “They simply weigh my words against my presentation—my age, my gender—and find the evidence wanting. It doesn’t matter. The proof will arrive in three days. It will just be written in casualty reports instead of ink.”

Three days later, the proof arrived. It did not come with heralds or triumphant horns. It came with the hollow, ash-streaked eyes of the few broken men who stumbled back through the great gates of Suyeong. The Silverbark Pass had fallen. General Choi was dead, his forces not just defeated, but systematically annihilated. The last standing army of Eunjang had been erased by the ruthless, precise brutality of Ganghak’s General Kang Wooyoung.

The kingdom was broken.

“I told you,” he said, his voice flat, devoid of accusation because emotion was a currency he had never learned to spend.

His mother did not look at him. Her gaze was fixed on the carved obsidian table, on the marker that represented their shattered forces. “What is done is done. We must discuss what remains.”

What remained was desperation.

“There is one asset they do not have,” the Queen said, her eyes finally lifting to her son. They held no maternal warmth, only the cold assessment of a tactician. “One they would covet. You.”

Sieun’s breath caught, a faint, almost imperceptible hitch. Behind him, his guard and only friend, An Suho, shifted, a low growl building in his throat.

“We will offer you to the new King of Ganghak,” she continued, her voice slicing through the tense air. “A public surrender. Our precious Omega prince, a gift to secure peace and mercy. It will appease their pride and halt their advance.”

“It makes him a slave,” Suho spat, forgetting protocol in his fury.

The Queen’s gaze flicked to him with disdain before returning to Sieun. “It buys us time. And it gives us a weapon they will never think to guard.” She stepped closer, her hand coming to rest on Sieun’s shoulder. It was not a comfort; it was the loading of a cannon. “You have a mind they cannot comprehend. Go into their mountain fortress. Be their beautiful, broken prize. Learn everything. Make the King himself trust you. And when he is blind to all else, you will show us the crack in their armor.”

Sieun met her eyes. He saw his duty, his purpose, the only value he had ever held in them. He gave a single, slow nod.

“I understand.”

 

 

In the granite heart of Hanseong, capital of Ganghak, King Keum Seongje read the elegantly scripted surrender scroll. At twenty-seven, newly crowned after the death of the father he had neither loved nor mourned, he felt not elation, but a weary satisfaction. The bleeding had stopped. His kingdom could begin to heal.

His war council, his most trusted men, stood around him in the torch-lit throne room. Na Baekjin, Park Humin, Go Hyuntak, and Kang Wooyoung, whose violent genius had delivered the final blow, now wearing a sharp, curious grin that didn’t reach his cold eyes.

“They offer their prince,” Seongje announced, his deep voice echoing in the vast space. He let the scroll roll shut with a soft crackle. “Prince Yeon Sieun. An Omega of ‘peerless grace and cultivated intellect,’ presented as a token of their submission and a plea for mercy.”

Wooyoung barked a short laugh. “A cultured pet. A pretty trophy to end a tedious war.”

“He is said to be exceptionally intelligent,” Hyuntak noted quietly. “A scholar and a strategist.”

“All the better,” Seongje said, his thumb brushing over the hardened wax seal of Eunjang. “A clever trophy is more valuable than a dull one. His presence here will be a constant, living reminder to every Eunjang loyalist of where power now resides.” His gaze lifted, meeting Wooyoung’s. “The terms mention he brings a personal guard. An Omega named Ahn Suho. See to their… secure transfer.”

Wooyoung’s grin widened, a flash of white in the dim light. “With pleasure, Your Majesty.”

 

.⋅˚₊‧ ⚜ ‧₊˚ ⋅

 

The journey north from Suyeong was a silent, winding funeral procession of two.

Prince Yeon Sieun and An Suho traveled with a minimal Eunjang escort—four weary soldiers who looked at their prince with a mixture of pity and shame. They were not guards of honor; they were deliverymen. The lush, green-canopied forests of home gave way to rocky foothills, the air growing sharper, thinner, scented of pine and cold stone instead of damp earth and blossom.

They rode in a simple, enclosed carriage, the royal crest hastily stripped from its door. Inside, the world was reduced to the rhythmic clatter of wheels and the muffled sound of hooves on the rough road.

Suho broke the silence first, his voice low and strained. “This is madness. You know that, don’t you?”

Sieun, who had been staring at his own hands resting in his lap, didn’t look up. “It is the only logical move remaining. Surrender meant annihilation. This… this provides a variable they cannot account for.”

“A variable?” Suho’s whisper was fierce. “You’re the variable, Sieun. They’re sending you into the wolf’s den as a meal. This ‘gathering information’ plan… it’s a death sentence wrapped in pretty duty. Your mother is sacrificing you to save face.”

“She is saving the kingdom,” Sieun corrected, though the words felt rote, rehearsed. “I am a tool. Tools are used for their purpose.”

“You’re a person!” Suho’s control snapped for a second, his hand slapping softly against the velvet seat between them. “You’re my friend. And they’re handing you over to Keum Seongje like… like a trinket. An Alpha who just crushed our forces. What do you think he’s going to do with you?”

Sieun finally lifted his gaze. His dark eyes were calm, fathomless pools. “He will see a prize. A symbol. He will likely keep me close, as a display of his victory. That proximity is what we need. The closer I am, the more I will see.”

“And what about what he will do?” Suho pressed, his cheeks flushed with anger and fear. “You’re not just a spy, you’re an Omega they’ve given him. He can do whatever he wants.”

A faint, almost imperceptible tremor passed through Sieun’s fingers. He curled them into fists. “Then that, too, will be part of the role I must play.”

Suho leaned forward, his voice dropping to an urgent whisper. “We could run. Now. Before we reach the border. We could disappear into the western wilds—”

“And leave Eunjang to burn down to ashes?” Sieun interrupted, his voice still quiet but now edged with a cold, final steel. “The mission is my responsibility. My duty. And you are here to guard me, Suho. Not to help me desert.”

“I’m here to protect you,” Suho retorted, hurt flashing in his eyes. “And right now, the biggest threat to you is this insane plan!”

“The biggest threat to both of us,” Sieun said, looking out the small window at the passing grey rocks, “will be Kang Wooyoung. The reports say he is… unpredictable. Feral. He is keum Seongje’s attack dog. He will be at the transfer. You must not engage him. You must not give him a reason to focus on you. Do you understand?”

Suho sat back, folding his arms. His jaw was set. “I understand that I don’t like it.”

“Your feelings are not relevant to the tactical reality,” Sieun said, and the clinical chill of the words made Suho flinch. It was the voice of the Queen’s son, the prince-strategist, the weapon. The friend was buried deep, locked away for survival.

They lapsed into silence again. The carriage climbed higher. The air grew so cold their breaths formed faint clouds inside the compartment.

 

 

The border was not a gate or a wall, but a wide, windswept plateau of scree and stubborn, thorny brush. The Eunjang escort halted here, their duty ending at the edge of their broken world.

Sieun and Suho stepped out of the carriage into the biting wind. Sieun had changed into the clothes of surrender: fabrics of soft, charcoal grey wool, unadorned, elegant in their stark simplicity. Suho wore his practical guard’s leathers, the only armor he had left. His sword was a familiar, comforting weight at his hip.

They stood together, two dark shapes against the vast, unforgiving sky, waiting.

The Ganghak contingent appeared as a dark line on the northern ridge, then descended like a rolling shadow. They moved with a disciplined, menacing grace. At their head rode a man on a massive, restless black warhorse.

General Kang Wooyoung.

He reined to a halt a few paces away, his gaze sweeping over them with an intensity that felt like a physical touch. He was all sharp angles and contained violence, his smile a slash of white in a handsome, ruthless face.

“Prince Yeon Sieun,” he declared, his voice carrying easily over the wind. It held a mocking parody of courtesy. His dark eyes, gleaming with interest, immediately slid past the prince and fixed on Suho. “And the guard. You can leave your weapons here. You won’t need them where you’re going.”

Suho’s spine straightened. He took half a step forward, placing himself subtly more in front of Sieun. “I am his personal guard. I stay armed.”

Wooyoung dismounted in one fluid, predatory motion. He closed the distance between them, his Alpha presence an immediate, oppressive weight that made the air feel too thick to breathe. He stopped too close to Suho, leaning in so his words were for him alone, a low, taunting murmur.

“Let’s be clear. You’re a pet, accompanying a prettier, more valuable pet. The only thing you’ll be guarding him from in Hanseong is boredom.” His eyes raked over Suho’s defiant face. “Now. The sword. Or I take it from you.”

The threat hung in the frozen air, palpable and violent. The Ganghak soldiers watched, still and silent as statues.

Suho’s hand twitched toward his hilt. Rage and helplessness warred in his eyes. A confrontation here would be suicide, and it would doom Sieun’s mission before it began.

It was Sieun who broke the deadly standoff. He didn’t raise his voice. He didn’t even look at Wooyoung. His calm, quiet command was aimed at the space between himself and his friend.

“Suho.”

A single word. It was the voice of the prince, accepting the first of countless humiliations. It was the voice of the strategist, sacrificing a pawn to protect the queen.

A tremor of pure, impotent fury went through Suho. For a long, searing moment, his blazing eyes remained locked with Wooyoung’s amused, challenging stare. Then, with a jerky, furious movement, he unbuckled his sword belt. The leather and steel hit the frozen ground with a final, hollow clatter that seemed to echo across the plateau.

Wooyoung’s smile turned genuine, and somehow more terrifying because of it. He straightened up, his eyes lingering on Suho’s flushed, furious face with open fascination.

“Wise prince,” he said, his tone dripping with false respect. He turned and swung back onto his horse with effortless grace. “Follow the column. Try not to get lost.”

As Wooyoung wheeled his horse around, Sieun’s hand found Suho’s wrist for a fleeting second—a silent apology, a plea for composure. Then he turned and began to walk, following the Ganghak soldiers toward the grim, granite peaks in the distance, where the fortress of Hanseong waited.

Under the roar of the wind and the crunch of marching boots, Suho’s voice was a thread of despair. “What now, Your Highness?”

Sieun kept his face a perfect, impassive mask, the one he had mastered over a lifetime of loneliness. But behind his eyes, the cold, brilliant engine of his mind was already whirring to life, analyzing Wooyoung’s demeanor, the soldiers’ formations, the terrain.

“Now,” he murmured back, the words lost to everyone but Suho, “We survive. And we watch.”

 

 

The approach to Hanseong was a lesson in intimidation. The road wound up the mountainside, carved from the living rock itself. The fortress-city didn’t just occupy the mountain; it seemed to have been vomited forth from it—towers of dark, sleek granite clawing at the grey sky, walls so high they stole the breath from Sieun’s lungs. It was brutal, unyielding, and magnificent in its stark power. A complete antithesis to the organic, woven beauty of Suyeong.

As they passed under the colossal, iron-reinforced gatehouse—the portcullis raised like a beast’s bared teeth—the world changed. The howling wind died, replaced by the echoing din of a military citadel: the clang of hammers on steel from a hundred forges, the shouted drills of soldiers in courtyards, the marching of countless boots on stone. The air smelled of smoke, iron, and cold.

But then they entered the inner keep, the heart of the royal residence, and the aesthetic shifted. The relentless grey stone remained, but now it was adorned, softened, warmed. Great swathes of crimson blazed everywhere—thick, luxurious carpets the color of spilled wine muffled their footsteps, heavy velvet drapes in rich burgundy hung between arches, and intricate tapestries depicting scenes of hunt and harvest added splashes of ruby and garnet. The crimson made the stone seem less like a prison and more like a jewel box, albeit one with impenetrable walls.

They were led not to a dungeon or a barracks, but to a spacious antechamber outside the throne room. A young man with an open, friendly face and warm eyes—Seo Juntae—bowed deeply.

“Prince Yeon Sieun, and you must be Ahn Suho,” he said, his voice respectful but not fearful. “I am to attend to your needs within the royal wing. King Keum will receive you shortly.”

Suho eyed him suspiciously, his body still taut as a bowstring. Sieun merely gave a slight, acknowledging nod.

Then, the great doors to the throne room opened.

The room was vast, lit by high, narrow windows and massive iron braziers.

At the far end, on a dais, sat the Onyx Throne.

And on it, King Keum Seongje.

Sieun had studied him, of course. Knew his age, his victories, the cold reputation of his father. But intelligence reports couldn’t capture the man’s presence.

Seongje was not lounging in indolent triumph; he sat with a relaxed yet watchful authority, like a mountain cat at rest. His broad shoulders filled the throne, his posture one of effortless command. His face was handsome in a stark, unforgiving way—sharp jaw, defined cheekbones, eyes that missed nothing.

Sieun walked forward, Suho a step behind. He kept his eyes lowered, the picture of submissive surrender. He stopped at the prescribed distance and knelt, the soft crimson pile of the carpet beneath his knees.

“Your Majesty,” he said, his voice clear and neutral. “I am Yeon Sieun. I am given into your… keeping.”

A beat of silence stretched. Then, the sound of boots on stone as Seongje rose and descended the dais. He stopped before Sieun. A hand entered Sieun’s downcast vision—strong, long-fingered, with the calluses of a warrior.

“Look at me.”

Sieun obeyed, lifting his head.

And for Seongje, the world narrowed.

He had heard the tales, of course. The poets and spies of Eunjang had not lied. But hearing of a masterpiece and standing before it were galaxies apart.

Yeon Sieun was devastating.

The famous silver hair, a hereditary mark of Eunjang’s royal line, was like captured moonlight, soft and fine. It framed a face of such ethereal, porcelain beauty it seemed impossible it belonged to a creature of flesh and blood. His cheeks held a soft, youthful curve, begging for a touch to see if they were as silken as they appeared.

And his lips. Gods, his lips. They were a soft, inviting pink, slightly parted, perfectly shaped. They were the kind of lips that belonged in sonnets, that promised whispers in the dark.

But it was the eyes that truly arrested Seongje. They were large, dark, and luminous, and they held a thousand silent emotions just beneath their calm surface: intelligence, resignation, a deep, resonant sorrow, and a flicker of something unbreakable. They were not the eyes of a broken victim. They were the eyes of a deep, still lake, hiding unknown currents beneath.

“Rise,” Seongje commanded, his own voice sounding slightly rougher than he intended.

Sieun stood, and Seongje’s hand, still outstretched, took his. The moment their skin met, a jolt, subtle but undeniable, passed between them.

Seongje had expected cold, clammy fear.

He did not expect the shocking softness.

Sieun’s hand was slender, his skin like cool, flawless silk over delicate bones.

It was the hand of a scholar, an artist, and it fit within his own calloused grip with a strange, unsettling rightness.

Every part of Yeon Sieun was more astounding than the stories. The reality of him was a physical blow to Seongje’s senses.

He was supposed to see a trophy.

A political tool.

A beautiful object.

He saw a complication.

A fascination.

Before he could speak again, a side door burst open with a clatter.

“Brother! You said we could see—!”

Two girls, mirror images save for their expressions, tumbled into the room. Princess Yuna, the Alpha twin, was all fearless energy, her eyes bright with curiosity. Princess Mina, the Omega, was slightly more hesitant, clinging to her sister’s sleeve, her gaze wide and shy.

Seongje’s stern expression melted into one of exasperated affection. “I said after the formal reception.”

“This is after!” Yuna declared, already stepping closer, her nose wrinkling as she scented the air. “He’s an Omega! A prince Omega!”

Mina, however, didn’t speak. She simply stared at Sieun, her shyness dissolving into pure, unadulterated wonder. She took a small, tentative step forward, then another. Very few high-born Omegas resided in the martial court of Ganghak. To see one so close, one who was a prince, who carried himself with such quiet grace… it was like a character from her storybooks had come to life.

“You’re so pretty,” Mina whispered, the words slipping out in a breath of awe.

An unexpected tension broke in the room. Sieun, who had been a statue of perfect composure, blinked. No one had ever called him that with such genuine, artless admiration. He looked at the young princess, really looked, and saw no malice, no calculation, only innocent wonder.

He did something then that he hadn’t planned. The faintest, most fragile ghost of a smile touched those perfect lips—a mere softening at the corners. It was there and gone in a heartbeat, but it transformed his face from beautiful statue to living, breathing beauty.

“Thank you, Princess,” he said quietly, his voice softer than it had been for the king.

Seongje watched the exchange, a strange tightness in his chest. He saw the unguarded warmth in Mina’s eyes, the flicker of startled humanity in Sieun’s. He saw Wooyoung watching Suho watch Sieun with protective desperation. He saw the entire, delicate, explosive puzzle laid out before him.

He cleared his throat, reclaiming control of the room. “Your chambers are prepared in the royal wing. Juntae will show you.” His gaze returned to Sieun, holding those deep, emotion-filled eyes. “We will speak more tonight. There is much to… discuss.”

The words were neutral, but the intensity behind them was not. He was no longer just accepting a trophy. He was beginning a new kind of campaign, and the territory was the mysterious, silver-haired prince now standing in the heart of his fortress.

 

.⋅˚₊‧ ⚜ ‧₊˚ ⋅

 

Juntae led them through a labyrinth of high-ceilinged corridors, the crimson carpets swallowing their footsteps. The air grew quieter, the military din fading to a distant hum. Finally, Juntae stopped before a pair of ornate wooden doors.

“These are your chambers, Your Highness,” he said, pushing one door open with a respectful bow.

The room was spacious and undeniably luxurious, another study in granite and crimson. A large canopied bed dominated the space, its hangings a deep, blood-red velvet. A heavy oak desk sat near a bookshelf already stocked with scrolls and leather-bound volumes. A fire crackled invitingly in a grand fireplace, fighting off the mountain chill. It was a prisoner’s suite fit for a king.

“And for you, Ahn Suho,” Juntae continued, gesturing to a smaller, plainer door set into the side wall of the main chamber. “Adjoining, as requested.”

Suho pushed the door open immediately, scanning the smaller room—a simple bed, a chest, a washstand. It was clean, functional, and most importantly, it shared a wall with Sieun. He gave a tight, grudging nod.

“I will have bath water and a meal sent up,” Juntae said with another courteous bow. “If you require anything, ring the bell pull by the fireplace. I am assigned to your household.” His gaze was kind, without a trace of the pity or scorn Sieun had braced for. Then he was gone, closing the main door softly behind him.

The silence that followed was profound.

Suho immediately began a methodical inspection of the room, checking the window locks, running a hand along the walls for hidden openings, peering under the bed. Sieun, however, stood motionless in the center of the room, his senses overwhelmed not by threats, but by the sheer, surreal reality of his situation.

He was here. In the heart of Hanseong. In the enemy king’s own wing.

His eyes were drawn to the only source of softness in the stone room: the tall, leaded-glass windows framed by more of that rich crimson velvet. He walked toward them slowly, his soft-soled shoes silent on the carpet. He did not open the latch. He did not step onto the small, iron-railed balcony beyond. He simply stood before the glass, parted the heavy curtain a sliver with two fingers, and looked out.

His breath caught.

Below, sprawled in a sheltered courtyard within the fortress walls, was a garden. It was not the wild, tangled beauty of the forests of home. This was ordered, deliberate, and breathtakingly vibrant. Neat gravel paths wound between explosions of color—roses in deep reds and pale pinks, beds of lavender and sage, orderly rows of flowering herbs. Lush green hedges formed living walls, and at the center, a willow tree wept gracefully over a small, clear pond. The late afternoon sun, piercing the mountain haze, gilded the leaves and made the petals glow.

It was a living poem of color and life, a stark, beautiful rebellion against the grim granite that surrounded it. The contrast was so terrible it was exquisite. It spoke of a will to create beauty, not just dominate. It was unexpected.

Just like the king.

Sieun let the curtain fall back, but the image was seared into his mind. He turned and leaned his back against the cool glass, closing his eyes.

The analytical part of his mind, the strategist, was already cataloging the layout, the patrol patterns he’d seen on the walls, the location of the garden as a potential meeting point or dead end.

But another part, a quieter, more vulnerable part he usually kept locked away, replayed the throne room.

Keum Seongje.

The man was nothing like the monstrous, war-hungry brute the Eunjang propaganda had depicted. His aura had been one of controlled power, yes, but not mindless cruelty. There was an intelligence in his gaze that had assessed Sieun not just as a body, but as a puzzle. And his hand…

Sieun’s own fingers curled slightly at the memory. The warmth of Seongje’s grasp had been a shock. It wasn’t the cold, dismissive grip of his mother, nor the clinical touch of a tutor. It was firm, alive, and it had sent a confusing current up his arm—not fear, but a startling, unwanted awareness.

He remembered the details with a clarity that was almost painful. The sharp cut of Seongje’s jaw. The way his dark hair fell slightly over his forehead. The surprising, singular imperfection that made his face human: a small, dark mole just beneath his right eye. It was a flaw that somehow anchored all that intimidating handsomeness, made it real, approachable.

And the twins. The Alpha sister’s bold curiosity, and the Omega girl’s whisper—You’re so pretty—had been a dagger to his carefully constructed detachment. No one had ever looked at him with such simple, uncomplicated warmth.

“It’s clear. For now,” Suho’s voice cut through his reverie. He had finished his inspection and stood with his arms crossed, his brow furrowed. “The lock on the connecting door is flimsy. I can break it down if I need to. The window leads to a twenty-foot drop onto stone, then the garden wall. Not an escape route.”

Sieun opened his eyes. The vulnerable prince was gone, tucked safely away. The strategist was back in command. “We are not here to escape, Suho. We are here to observe.”

“He looked at you like…” Suho trailed off, anger and worry warring on his face. “And that general. Wooyoung. He’s a predator.”

“All the more reason for precision, not panic,” Sieun said, his voice low and even. He moved to the desk, tracing a finger over the grain of the wood. “The king is intelligent. He will test me. I must be… what he expects, and yet more. I must be intriguing enough to keep close, unthreatening enough to let my guard down.”

He looked back at the window, where the last of the sun’s light painted the crimson curtains with gold.

“The garden is a weakness,” Sieun murmured, more to himself than to Suho. “A place of softness in a fortress of stone. Everyone has a weakness. Even kings.”

But as he said it, the memory of that warm hand, that curious, intelligent gaze, the mole under the eye, and the ghost of a king’s smile for his sisters flashed before him. A cold knot of doubt, unfamiliar and treacherous, tightened in his stomach.

He is not what I imagined.

And that, the mastermind knew, was the most dangerous variable of all.

 

 

Notes:

this was not supposed to be this long GOD HELP MEEEEE
anyways, enjoy 😭😭