Two detectives race the clock to keep a young boy safe when he is targeted by a powerful and dangerous cartel. Their investigation leads them into danger and they must decide who it is they really serve and protect.

The team track down a serial killer who lures his victims into isolated areas before killing them live on social media. Meanwhile, Syd has a dangerous secret that clashes with McKenna's complicated past.

Syd and McKenna are called to investigate when a body seems to plummet from the sky; the partners realise they need to trust each other to escape the ghosts of their pasts.

Syd and McKenna must get Knox's fentanyl into police custody without leaving a clue as to their involvement, a task made more difficult when McKenna is distracted by Izzy's strange behaviour, and Syd sees a ghost from her past.

Syd and McKenna try to find the killer behind the death of a transgender woman, while fighting with their own personal complications; Syd must face her past as the hunt for Knox intensifies; McKenna helps Izzy deal with her grief.

McKenna is unable to keep hiding the truth about her mother's accident from Syd; Arlo plots against people Syd loves; Syd and McKenna continue to hunt for the killer of the transgender woman and her fiancé.