Seon Jin lives a life of quiet terror, hiding behind the shadow of a father the world adores as a charismatic, successful CEO. While his classmates see a frail, bullied boy with a glass eye, the horrifying reality is far darker: Jin is the unwilling accomplice to his father’s gruesome hobby as a serial killer. For years, he has remained trapped in a cycle of complicity and fear, acting as the lure for his father’s victims to ensure his own survival. This fragile status quo shatters when Kyun Yoon, a kind and resilient transfer student, enters his life and becomes the first person to show him genuine warmth. But as Jin’s heart begins to stir with hope, his father sets his sights on Kyun as his next target, forcing Jin to make a harrowing choice between the blood ties that bind him and the girl who makes him want to be human.

Desperate to protect Kyun, Jin embarks on a high-stakes game of cat-and-mouse against a man who is always three steps ahead. This rebellion ignites a fierce internal battle as Jin grapples with his own identity, fearing that the monster in his blood might be stronger than the boy he wants to become. As the masks slip and the psychological warfare intensifies, the stakes climb to a lethal peak where every alliance is a gamble and every secret is a weapon. Driven by a newfound resolve, Jin transforms from a victim into a protector, fueled by an unwavering dream to dismantle his father’s legacy of death. He will risk everything to break the chains of his upbringing, determined to save the only light he’s ever known and finally claim a future that is truly his own.