One year after graduating from college, Lin Jiamin, hoping to earn a high salary, takes a job at an entertainment venue called "Changye Xinghuo" on a friend's recommendation. There she meets her coworker Gu Yaoyao and their boss, Zhang Yang.
On a stormy night, a man is found dead in the corridor. An accident? Murder? When the victim is his own daughter, what will Lin Fuxiang choose to do as her father?
Not long afterward, Gu Yaoyao is found dead by suicide in the bathroom of her rented apartment. Though Lin Jiamin was not there, she becomes a key figure in the evidence, holding the decisive proof that could determine whether the death was suicide or murder.
After investigating, Li Min, captain of the criminal investigation brigade, concludes that Gu Yaoyao's death must be connected to their boss, Zhang Yang. But without sufficient evidence, the police cannot arrest him. Just as they are struggling to find proof, someone comes forward with crucial evidence that could prove Zhang Yang's crimes. At that point, less than three days remain before the evidence disappears...
A story revolving around the dead. In the long night, the echoes never cease.