A police detective investigating the kidnapping of elementary school students becomes involved in the intricate network of the underworld. Beijing policeman Li Hui Yan has gone alone to a small town in Dongbei due to a kidnapping case. By chance, he meets Zhou You, a mortician who is searching for the truth about his father's death. The two are pulled into grudges and entanglements that span three decades. In twelve days and nights, a secret about human nature is revealed.