You were a high-ranking spy, one of the best, feared in every nation. For years, you carried the scar of your brother’s death until that night when a letter arrived, sealed with his handwriting. Alive? Impossible. But the trail led you to one place: the City of Desire, a kingdom where any wish could be bought… if you had enough to pay.

Disguised as a wandering writer, you slipped into a grand party held in a mansion that pulsed with wealth and secrets.

Every door you opened tempted you. One spilled over with golden treasure, enough to buy ten empires. Another revealed mountains of food, fruits dripping honey, wines older than kingdoms. A third… a wild debauchery, bodies and laughter tangled in sinful pleasures.

But then you saw it. The large crimson door.

You pushed it open, just a crack, and froze.

Inside, a man in a black-red suit sat like a king, legs spread, glass of wine in hand. His client knelt before him, pleading for a deal. The man looked bored, twirling a ring on his finger.

When the client lost patience and fired a gun, the bullet hung in midair, like time itself bowed before him. With a flick, the bullet reversed and tore through the man’s chest.

And then… his eyes shifted. Right at you.

Your instinct screamed to run. But your body locked in place. His gaze pinned you, like invisible chains.

Suddenly hallucination. You saw your brother standing by a hidden stair. “This way,” he whispered.

“Brother!” Tears burned as you chased him, down into a hidden chamber. Ancient scrolls, thousands of them, filled the underground. You flung yourself into his arms only to freeze as the embrace grew colder.

The face shifted. The voice deepened.

“Interesting,” he murmured, gripping your chin, his breath brushing your ear. “Who do you think I am?” His eyes burned like embers. “Your scent… it’s different.”

“Monster!” you snarled, dragging out your dagger, slicing toward his chest. But he moved like shadow dodging with ease, smirking as if your skill only amused him.

You slashed with your dagger, but the mafia demon only smirked. With a flick of his fingers, the blade was ripped from your hand, floating midair before it whipped back toward you.

Steel kissed your skin. A sharp sting tore across your arm, blood blooming instantly.

You stumbled back, clutching the wound, but his crimson eyes only gleamed darker.

“Careful,” he drawled. “Your blood smells far too tempting.”

Rage surged through you. Without thinking, you spun and hurled yourself into the underground river. Cold water swallowed you whole, dragging you down into the abyss.

His hand clamped around your ankle, dragging you down into the black water. You thrashed wildly, lungs burning, but his grip only tightened. His crimson eyes glowed like embers beneath the waves.

“You think you could get away?” his voice rumbled through the water, distorted but cold.

“You monster—let me go!” you kicked and struggled, but his strength was merciless.

Then it happened.

Your blood still seeping from the cut on your arm, unraveled into the water like crimson smoke. The instant it touched the currents, the ancient scrolls hidden in the depths began to shift, glowing, writhing like living things.

The demon’s eyes snapped wide. My contract… it’s dissolving.

For the first time, his grip faltered. His body seized as though an invisible weight dragged him down too. A suffocating pressure crushed his chest. Panic flickered across his sharp features.

Am I… drowning? Impossible… A powerful demon cannot drown.

He dove after you, dragging your faint body to the shore. Coughing, drenched, his eyes widened as he saw the scroll rewritten, restored, bound to your heartbeat.

“Could it be…” he muttered, brushing his thumb across your lips, “…my demon contract is now synced with this girl’s vital signs?”

For the first time, the predator looked shaken.

And you, unconscious, were now the key to his immortality.