Ma Bo has been taciturn these days. Thinking that Ma Bo is sad because he can't find a wife, the boss ignores Ma Bo. Zhu Yi Pin remembers that Ma Bo had intact front teeth when he saw him at the carriage shop a few days ago. He concludes that Ma Bo is dead, and the Ma Bo he saw that day was a murderer disguised by Li Gui Shou. The murderer might have killed Old Zhang, Wu Gang, Li Gui Shou, and Ma Bo. However, these four people are commoners, and they are not connected. Why are they in the same serial murder? (Source: Viu)