After a life-altering incident, John Nolan decides to pursue his dream of becoming a police officer. The force's oldest rookie, however, is met with scepticism from some higher-ups and ridicule from younger officers.

Nolan must confront his personal moral instincts after he encounters a kidnapping victim; Lucy's new training officer tests her patience; Jackson must confront his failures head-on.

After Nolan and Talia lose control of a crime scene, they begin to debate whether people are fundamentally good or bad; Lucy worries Tim is enabling his wife's destructive behaviour at the expense of his own welfare.

When they're assigned to temporary training officers, the rookies learn valuable lessons. Nolan makes a career-making bust, Jackson overcomes his fears, and Chen has an insightful conversation about relationships.

The rookies and their training officers partake in a traditional competition to get the most number of arrests. While some play to win at all costs, some refuse to participate.

The team must help capture a cop and his former mentor after they become fugitives following an assault. Meanwhile, Officer Tim Bradford instructs Officer Lucy Chen on how to predict the moves of criminals in order to capture them.