Lin Chen, once a rising star in criminal investigation, lies low for five years before returning under an alias to uncover the truth behind his father's murder and clear his family's name. He meets Su Rui, a female captain seeking the truth about her older brother's death. From suspicion and probing to entrusting their lives to each other, the two form an alliance for revenge.
Their ultimate enemy is Zhou Zhenghong, who presents himself as a Confucian businessman but secretly controls the vast criminal empire known as Dragon Scale. Lin Chen and Su Rui follow the clues into a dark web of human experimentation and collusion between officials and business interests. As the countdown to the Nightfall Plan looms and the entire city grinds to a halt, these partners, both scarred by the past, must kindle one last light in the ashes of their convictions and pursue justice in a mission that seems all but impossible.
