Eavesdropping on the life of Sidney Chambers, a charismatic, charming, crime-fighting clergyman, and his partner in crime Police Inspector Geordie Keating, became a highlight for the audience who revelled in their on screen partnership. Geordie's plain-speaking, down to earth approach to policing complemented Sidney's more gentle technique of coaxing information from witnesses and suspects. Their unlikely pairing became a true friendship as each offered a different insight into the crimes they unravelled.
It's 1955 in Grantchester, local vicar Sidney Chambers [James Norton] meets with the new archdeacon, Gabriel Atubo. Acknowledging that Gabriel's predecessor was dispatched under some controversy and embarrassment, Gabriel questions whether he can rely on Sidney to rebuild trust in the church and lead by example. Sidney reassures him he can be counted on.
A village cricket match - Grantchester vs Whittlesford - brings the community together. Sidney and Geordie form a batting partnership and they swat away everything the Whittlesford bowlers can throw at them until Geordie spots Margaret in the crowd and falls foul of a thundering Yorker!
A quiet day in Cambridge is thrown into disarray as Leonard and his new lady friend Hilary are witness to an armed robbery at the post office. With a gun pointed in his face, Leonard attempts to talk down the masked culprit and receives a strike to the head for his bravery.
Back from a morning run, Sidney is joined by former flame Amanda at the vicarage. Having agreed not to take their relationship forward, they exchange pleasantries but keep their distance. As Amanda leaves, Mrs Maguire encourages Sidney to stay strong. Sidney's longing for Amanda only worsens when he later sees her with estranged husband, Guy. Could Amanda be contemplating a return to her old life?
As Leonard is hailed a hero, Sidney and Geordie investigate the post office robbery and it soon becomes clear, this is the first of many. As the robberies become more violent, Sidney and Geordie must work quickly to unmask Cambridgeshire's very own Bonnie and Clyde.
After a guilt-induced sermon about desire and duty, Sidney questions himself about Amanda. He wants to resist but soon finds himself in an embrace with her, which is spotted by Leonard who berates Sidney for being such a hypocrite.
Meanwhile, Mrs Maguire is shocked when she is met by a visitor on her morning walk – the face from the past leaves her rattled to the core and she enlists Sidney's help in dealing with her emotions.
Having left his Grantchester life behind to do some soul searching, vicar Sidney Chambers finds himself heading toward a Romani travellers' camp in Lincolnshire.
Having tracked down the culprit, Sidney tells himself he is there to retrieve Mrs Maguire's life savings from the man who stole them but it soon becomes apparent, Sidney is just running from his old life and has no idea what he is going to do.
Seduced by the intoxicating, welcoming community he finds himself in Sidney begins to wonder if he'll ever return home. But murder is never far from Sidney's door and when one of the community is killed, Sidney the ‘outsider' is suspect number one.
On a Sunday morning in Grantchester, Sidney visits the Archdeacon to discuss his resignation. Sidney has lost his faith in a church that won't allow him to be married to the woman he loves. With a heavy heart the Archdeacon tells Sidney he must go away and write a resignation letter in order to make it official.