Ma Desheng is a policeman who was responsible for the corpse dismemberment case many years ago. However, due to limited conditions, it was not solved that year. For a policeman, not finding the murderer and telling the family the truth is a very self-blaming thing.

Many years later, although Ma Desheng had retired and lived the life of an elderly person, the corpse dismemberment case was like a thorn in his heart, so when Wang Xiang found him, he did not hesitate.He came out of the mountain again and found the murderer with Wang Xiang and others.