Black Snake's Past: the Living Dead

This is a revenge story about the living dead. In 2003, a case of missing brothers and sisters occurred in the busy town of Wushe. Through investigation and interviews, two police officers, Xiao Yong and Chen Xiaobing, discovered that this disappearance case was actually linked to the kidnapping of a brother and sister that occurred ten years ago. And the two of them learned that the entire family died in the kidnapping case of a brother and sister ten years ago. The five people who kidnapped the brothers and sisters ten years ago died or disappeared one after another after being released from prison. The last mastermind to be released from prison survived. Who should pay for his sin? Is it himself or his family?