Lik-kei and Chung-ying inspect some suspicious batch of apparel. But they have not found anything. Ho-fan then wants to sort out the apparel. While he is ironing some garment, each of the trio becomes disoriented one after another. The next day, Chung-ying surprisingly sees Li-kei sleeping in the same bed as her. They have even mutually switched clothes between them. The same things have also happened to Ho-fan and Wing-yum. But the quartet cannot remember anything about last night. Chung-ying goes along with Ho-fan to undergo hypnosis in an attempt to retrieve lost memories. But Ho-fan cannot be hypnotized. Instead, Chung-ying recalls she and Lik-kei taking footage of themselves the other night. But that clip is not on her phone. W reminds Lai-yiu not to let anyone know her whereabouts. Lai-yiu then moves into the Yip household. Ming-kwan helplessly agrees. Lik-kei tells Ming-kwan to get closer to Lai-yiu to gather intelligence.
Because of a fatal shooting case, plain-clothes Sergeant Ko Lik-kei runs into a “dull” and “troublesome” witness called Lee Ho-fan. Lik-kei is instructed to protect Ho-fan at all times. Initially, the duo are strangers that cannot stand each other. They then gradually get along. Meanwhile, an apparel company of which Ho-fan is a major shareholder is found to have involved in illicit dealings. Yip Cheung-lok and his son Yip Ming-kwan, who are member of senior management, are associated with these activities. Lik-kei teams up with Ho-fan and Ho-fan’s younger sister Lee Chung-ying, who is a barrister by profession, to investigate. Lik-kei and Chung-ying get entangled in a relationship in the process. Also, Lik-kei’s elder sister Ko Wing-yumand Ho-fan get along sometimes and provoke each other at other times. Fate has brought the foursome together, causing a case that has remained unsolved for more than twenty years to be reopened.
