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.

Adapted from the novel "The Light of the Dark Night" (黯夜之光) by Lou Xiao Peng (娄霄鹏).