Unriddle

Zhang Yuze informs Xiao Man that his former girlfriend, Ivy, was murdered and he can't forget her.

Yuze, Andrew, Zhirong and Wu Guosheng gather to pay their respects to their former partner Old Cai who was murdered fifteen years ago. Zhirong informs Yuze that he has a feeling he's being followed by Wu Guosheng.

Zheng Yi witnesses Yuze chasing Shan Fan. Shan Fan is caught and tries to bribe Yuze into letting him go. Zheng Yi is distracted and when she tries to locate Yuze, he has disappeared along with Shan Fan and the money, leaving only blood behind.

Andrew finds Zhirong searching Yuze's flat for clues. He turns up a threatening note which Andrew believes may link his disappearance to the event 15 years before. Andrew decides to tell everyone that Yuze has chosen a corrupt way of life and has disappeared with the bribe money.

Xiuling's father is captured; Xiao Man begins to investigate the case; Xiuling realizes that all the things her father did were because he loved her.

Xiao Man's cold, impersonal approach doesn't always work, so Zheng Yi steps up with her warm, personal way to gather the needed information. When they investigate the area where Xiao Bo went missing, they realize that Mei Yue's information doesn't match the evidence.