Case #1:
Inspired by her brother's girlfriend, Karmen Kwok joins the ICAC as an assistant investigator. During the initial training, she constantly makes mistakes, but her proactive attitude and dedication leaves a deep impression on instructor Ruco Chan.
While visiting her grandmother, senior investigator Natalie Tong overhears the neighbours talking about how Lawrence Cheng, a candidate for the District Council by-election, is bribing voters using clever tactics that circumvent the law. They all have a different view on whether Lawrence's actions constitutes as illegal. Natalie tells her superior Chris Lai about Lawrence's case. It turns out that the ICAC has already receive complaints and is preparing an investigation.
Case #2:
As Karmen completes her training, Ruco is also transferred back to the front lines. He partners with Natalie to investigate a case involving a wristwatch corporation bribing tour guides. As it is a complex case, principal investigator Elena Kong decides to personally participate in the investigation. They encounter many problems as they gather evidence. Ruco and his long-time girlfriend Elaine Yiu are each busy with work. Elaine makes huge profits in real estate and is gradually becoming blinded by money. One time, she mentions about a conspiracy between a real estate agent and an employee of the developer to fraudulently earn commission. Ruco points out that their actions may have violated the law and reminds Elaine not to join them. They part on bad terms.