When a boy is targeted by a powerful cartel, two detectives with complex pasts race the clock to keep him safe, but when Syd's personal quest for justice threatens their efforts, the pair must decide whom they really serve and protect.

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.

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.

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.