The special homicide case that was unsolved in 1997 resurfaced 13 years later. Criminal policeman Wei Zhengrong, who wasn't able to find out the real murderer that year was traumatised and left the front line. The once fledgling new policeman Lu Xingzhi grown from his innocence and has become a meticulous criminal investigation expert. The many coincidences of the case brought the master and apprentice together again to hunt down the real culprit.

Two close friends and fellow cops, Tom and Lola, end up living and working together after Tom's marriage breaks down, blending crime procedural with feel-good family elements.