Lynn and Lucy are life-long best friends, their relationship as intense as any romance. Neither has ventured far from where they grew up. Lynn, who married her first boyfriend and whose daughter is fast growing up, is delighted when the charismatic, volatile Lucy has her first baby boy. Lucy, however does not react to being a mother as Lynn expects. Soon, they find their friendship is tested in extreme circumstances.

Tom Brittney宣布这会是自己出演的最后一季，Rishi Nair加入饰演新牧师Alphy Kotteram，并将在潜在的后续新季中接替主角位置。

As DI Geordie Keatingand Reverend Alphy Kottaram continue to work together as a crime-solving duo in scenic Grantchester, they must also support each other through changing times, family struggles, and personal secrets. This season, Alphy feels like he’s found a home, but he’s forced to confront secrets he’s kept close to his chest. Will he be able to let anyone fully in, or must he confront truths about himself first