In the 57th year of the New Era, Hongwan, the foggy port city.
Lu Hansheng, a former ace sniper and current criminal profiler, is a rational guardian of the rules and uses procedural justice to heal the bullet holes left by his partner's sacrifice. Cheng Moxiao, a former anti-narcotics undercover agent, is now a criminal police officer in the serious crime team. He is a wild and untamed intuitive hunter who believes in the outcome of justice. Every scar on his body is the price of surviving outside the rules.
The mysterious death of an engineer handcuffed these two women who disliked each other into a partnership. Behind the case involves a human experiment scandal that was buried during the "Great Fall" fifty years ago. When the dusty "Styx Project" is awakened, sleeping evil opens its eyes in the shadows of the city, and procedures and intuition, rules and wildness continue to collide.
Rainy nights, old wounds, lies, trust. They are each other's most dangerous vulnerability, and the only ones who can fix it. In the pursuit of justice, they polished off each other's sharp edges, and used their flesh and blood to mold each other into a shape that could stand side by side over countless long nights.
This is the story of two scarred souls who serve as each other's beacon and pierce the fog.
Purpose: Be a beacon for each other on the thorny road of pursuing justice, learn to embrace the warmth and redemption of human nature while adhering to principles.