KBR is a large comprehensive research building with multiple "doppelgangers". Tang Yu, who lives in one of the "doppelgangers", leads a dark life every day. On a special day, he met a "top operations officer" who was transferred from the headquarters and became his partner by accident. In mission after mission, Tang Yu gradually had a different view of this partner. Behind every glamor, there is always an unknown story. In the cases that are solved again and again, what is hidden among the clues at the scene? Who is the mastermind behind each case? Why did Chu Lin, who had the "supreme operational command authority", choose to leave? Family affection, betrayal, what is hidden under the friendly masks? What is it that can turn brothers into enemies overnight? These truths will eventually be revealed...
Intention: Fight hard in the dark