Detective vs. Sleuths

After executing the perpetrator of a murder case unsolved for thirty years, the assassin nicknamed "Super Sleuth" announces he'll continue to bring his personal brand of justice to other elusive killers. The police, believing this a challenge to their crime-solving abilities, assign their own super sleuth, Wang Zhenfeng, along with retired "super sleuth" Uncle Xiangyun, to analyze long-dormant cold cases and find the killers before they're killed. A succession of successfully executed Super Sleuth-style murders leads Wang to doubt Uncle Xiangyun's true identity. Meanwhile, the three super sleuths engage in a battle of wits before the next execution takes place.