Nolan teams up with new night detective Pablo Armstrong for a murder investigation case that results in an unexpected reunion with a former love interest. Meanwhile, Officer Bradford reluctantly accepts help from Officer Chen as he prepares for his sergeant exam, and Officer West pursues an unconventional move after finding himself in need of a new home.

Officer Nolan gets off to a rocky start after being introduced to his new training officer, Nyla Harper, who has an unconventional approach to police work after her stint as an undercover detective. Meanwhile, Officer Bradford struggles to think of an appropriate birthday gift for Rachel, and Officer Lopez finds herself navigating a case that triggers a personal memory.