Officer Nolan and the LA division of the FBI enlist the help of FBI trainee Simone Clark when one of her former students is suspected of terrorism following an explosion at a local power station.

The team alongside the LA Division of the FBI are in a race to stop bombs that have been scattered throughout the city by a suspected terrorist. Meanwhile, the joint task force is suspicious of the CIA’s involvement in the situation.

Officer John Nolan is assigned his first rookie, Officer Celina Juarez, whose unconventional approach to police work poses a unique challenge for him.

With help from the FBI, Detective Lopez puts everything on the line to help Elijah Stone take down a gang leader in exchange for her safety. Meanwhile, Nolan and Bailey must deal with the secrets and shady dealings his late mother left behind.

Sgt. Grey helps the team prepare for their biggest mission yet. Meanwhile, Aaron, Lopez, Celina, Tim and Smitty discover a surprising connection in their case.

Now recovering from a gunshot wound and feeling the effects of his age, John and the team welcome two new rookies and continue the hunt for two dangerous inmates with very personal vendettas following their prison escape.

John and Harper work together to catch Oscar. Angela investigates a bank robbery. Lucy and Tim learn to adapt to her new schedule, and Miles' first date takes an unexpected turn.