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 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.

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.

With McKenna's help, Syd searches for Jen's killer as she grieves the loss of her friend. The death of a Koreatown legend has the community up in arms wondering who could be responsible.

As the team searches for the culprit behind the Koreatown crime surge, McKenna is triggered by memories from her experience in Iraq. Syd discovers a tape of Jen with an unexpected client.

The LAPD team races against the clock to rescue one of their own.

When Emma goes missing, Syd will stop at nothing to bring her back home to her family. An undercover McKenna attends a veteran's retreat that could be sourcing the highly skilled Koreatown criminals.