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?

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.

Syd, McKenna and the team band together as they race against the clock to save one of their own, finally coming face-to-face with their greatest enemy.