After Deering and her team lose the serial killer case to Maclaren, the cops see a chance to redeem themselves by investigating a dangerous new street drug.

Dinah invites Cathy, the girl she saved, to stay at her house, but their arrangement causes trouble for the investigation. After watching a teenager overdose, Viv and her team trace a bad batch of drugs to a wealthy couple.

The search for another girl abducted by the serial killer leads to a big breakthrough.

Dinah attends to a man who walked out in front of a car to commit suicide, but the case becomes more complicated when the police inform the next of kin. Viv's team desperately searches for a missing girl, concerned she may be the serial killer's next victim.