Following the lives of five new and inexperienced police recruits in their mid-20s who trained together and must now learn at first hand the hardest kind of policing there is: as big-city crime-fighters. Andy faces a volatile gunman when the high-risk takedown of a suspect does not go as planned.

The officers assist in an undercover operation involving a suspected supplier of armor-piercing bullets, before taking part in a police-only boxing tournament.

McNally, Peck and Diaz take to the streets, posing as prostitute as part of a city-wide sting operation, while Nash assists detective Callaghan in investigating the murder of an unidentified teenager.

Andy and Traci respond to a break-in at an upscale address. When the crisis appears to be over, Traci hurries away to handle a personal emergency, leaving Andy in the lurch when she is later confronted by an armed suspect.

Andy's romance with Callaghan becomes complicated when they disagree over how to handle a witness in a murder case. Meanwhile, the other rookies discover the shocking truth behind evidence from a fatal traffic collision.