Detective Inspector Mike Shepherd is sent from Auckland to Brokenwood to investigate a local police officer. With a possible murder investigation underway that might link the two, Shepherd takes charge. After the investigation, Shepherd reassesses his life and decides to stay on indefinitely, even though it means a demotion to Detective Senior Sergeant. Brokenwood is a seemingly quiet country town where Shepherd, who has an unconventional approach to police work, is assisted by local Detective Kristin Sims, who is precise and efficient at her job, to solve murders. As the series progresses, the working relationship between the two moves from rocky to functional as they begin to appreciate each other's talents.