A troubled engineer faces pressure at work and problems at home with his moody wife. American expat Chuck, rescues him from the brink of despair and becomes an unlikely mentor.
When Shuai Jiamo, who is obsessed with mathematics, stumbles upon a historical problem in Jinhua County, he was met with multiple obstacles in his attempts to correct the mistake, triggering a tension between various stakeholders.
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.