The Mourner Who Comes with the Evening Rain

Three years after the assassin organization Dark River disbanded, its leader Su Changhe and top assassin Su Muyu have settled in a secluded valley and opened an apothecary to make a living. Then a sixteen-year-old case crashes into their quiet lives like a sudden storm: Shen Hanzhou, the sole survivor of the Shen family, marks his targets with a withered locust leaf and begins hunting down the twelve people involved in his family's massacre. Mu Qingyan goes missing, and Xie Yunshen is murdered. Their peaceful days are over.

Su Muyu vows to protect Su Changhe. Forced to investigate the truth, the two uncover that the real culprit behind the massacre was Xu Tianba, a salt smuggler. They strike a deal with Shen Hanzhou and join forces to assassinate Xu Tianba on a rainy night in Yangzhou. But the revenge does not end there. On their way back, they are ambushed by the authorities and the remaining members of the salt gang. Su Changhe is gravely wounded, and it is revealed that he has been poisoned with the Heart-Locking Pill for sixteen years.