The LAPD, FBI and Interpol work with Monica Stevens in Prague to target high-value terrorists.

When the president visits Los Angeles, the LAPD teams up with the Secret Service to ensure his safety and assess any major threats on their watch list. Meanwhile, Miles's instincts are tested and Tim takes on a new role.

Nolan conducts a silent arrest while Lucy and Celina rush to save a kidnap victim. Harper and Lopez work to outwit a killer, and Miles meets someone from his past.

While out in the city, Nolan and Bailey witness a murder in public and immediately spring into action in the hopes of finding the person responsible. Meanwhile, Angela and Wesley have a big life decision that may affect their future.

Lieutenant Grey and the FBI task force recruit a former colleague to expose a criminal network. Meanwhile, Nolan, Miles, Lucy, and Celina investigate a puzzling officer-involved shooting.

On Valentine's Day, the team hunts an arsonist. Celina believes Miles is cursed and tries to break it.

Harper and Lucy work undercover in Baja investigating two women's murders. Nolan and Bailey deal with their long-distance relationship.

Nolan and Garza's operation fails. Lucy and Tim's relationship faces a challenge from a surprise guest. The team hunts for a suspect across the city.

Harper and Miles feel the weight of their recent mistakes while Harper is tasked with training Miles. Nolan and Celina are dispatched to a robbery call where Nolan encounters a familiar face.

Nolan, Harper and Miles face a dangerous situation. Meanwhile, Bailey conducts a covert investigation at the Pentagon.

Lucy returns to work as an unexpected twist hinders the Liam Glasser case, and a familiar face helps track down a killer.

The FBI and LAPD join forces to protect Bailey, while Wesley's campaign is threatened by a public scandal.