Tracking down a serial killer who lures his victims into isolated areas before killing them live on social media; 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 realize they need to trust each other to escape the ghosts of their pasts.

Time is up – Syd and McKenna need to get Knox’s fentanyl into police custody while leaving no trace of their own involvement. But can they pull it off when McKenna is distracted by Izzy’s strange behavior and a ghost from Syd’s past returns to haunt her?

While fighting with their own complications, Syd and McKenna try and find the killer behind the death of a transgender woman. 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.

Syd and McKenna ramp up their personal search for Gabriel Knox and let the Bens in on their search for Arlo. Syd faces a family crisis. McKenna must make a difficult choice.

McKenna is forced to come clean about her past to her husband, and both she and Syd attempt to convince him to bend the rule of law to save a life. In the meantime, our team find themselves trailing a group of thieves who managed to steal million of dollars' worth of untraceable diamonds.

It's busy for our team of detectives as they continue to investigate the case of the missing diamonds, and the task force executes a major drug bust. With the treat of Knox looming, both Syd and McKenna must confront some of their deepest secrets yet.

As their pasts continue to crash into the present, Syd and McKenna discover that an unknown player has been manipulating them all along. Meanwhile, the search for the missing diamonds continues, just as McKenna is face with a impossible choice; her brother or her future.