Hwang Hyunjin, 23, is one of Seoul’s most respected detectives—or so everyone believes. In truth, he’s a cunning gang member working undercover at the police station, gathering intel to protect his organization and manipulate the law from within. Cold, sharp, and unreadable, Hyunjin keeps his identity sealed behind his badge and charisma.

Kim Seungmin, 20, is a quiet yet strong single father raising his 5-year-old son Ahin—a boy who shares his exact features. After being harassed and taken advantage of at just 15 by a manipulative older girl, Seungmin found himself abandoned with a newborn when she fled to America. He raised Ahin on his own with help from his two loyal best friends, Felix and Han, trying to give him a peaceful life.

But peace ends the moment she returns to Korea—this time with six bodyguards and a disturbing obsession to claim back what she left behind. After a break-in and escalating threats, Seungmin reports the incident to the police. That’s when Hyunjin enters the picture.

—

The hum of the station was steady—buzzing with detectives typing, suspects whining, and printers spitting out reports. Hyunjin leaned against his desk, badge clipped neatly, black button-up perfectly creased. To everyone around him, he was Detective Hwang—trusted, calm, deadly when he needed to be. To the streets that ran after midnight, he was the right hand of the city’s most feared gang leader.

“Detective Hwang, you’ve got three walk-ins. Disturbance call,” a rookie said, chewing on a pen cap. “One of them has a kid.”

Hyunjin didn’t flinch until he turned the corner.

Standing at the front was a boy—no, a man—but with the gentlest eyes he’d ever seen. Kim Seungmin. Pale skin, soft hair that looked hastily brushed, a fitted hoodie hiding trembling hands. Beside him stood two boys—Felix, radiant like sunlight, whispering to calm the child in Seungmin’s arms, and Han, who looked ready to throw fists.

The child…

Hyunjin stared.

The boy clutched to Seungmin’s neck had the same sharp almond eyes, the same slope to his nose. Ahin. His black hair flopped to one side, small arms wrapped tightly around his father’s neck.

Hyunjin’s gaze flicked up, locking eyes with Seungmin’s for the first time.

Something broke.