After the robbery of a train filled with valuable auction items turns deadly, the team is called to investigate. Meanwhile, Officer Chen has doubts about being Sergeant Bradford's aid and is upset when he doesn't give her the recognition she deserves. Elsewhere, Officer Harper takes matters into her own hands and makes a life-changing decision about her personal life.

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.