James Norton and Robson Green return as the local vicar and detective inspector in the Cambridgeshire village of Grantchester. It is 1955, and Sidney Chambers (Norton) meets the new archdeacon, Gabriel Atubo (Gary Beadle).
Acknowledging that Gabriel’s predecessor was dispatched under some controversy, Gabriel needs assurance that he can rely on Sidney to rebuild trust in the church. Later that night, Sidney is on the dance floor with his old flame Amanda Hopkins (Morven Christie), while Sidney’s best friend DI Geordie Keating (Green) sits nearby with wife Cathy (Kacey Ainsworth), the spark a little dimmer in their own relationship.
Back home, Sidney finds a dead bird laid out on his record player, but he is distracted by a telephone call from Geordie – Dr Terrence Atwell has been found dead in suspicious circumstances. At Dr Atwell’s house, Sidney finds a photo of him outside Dapple Oak, an institution for the disabled, and on the bed, is another dead bird. But when the recent death of the matron of Dapple Oak is also confirmed as suspicious, Sidney and Geordie set out to investigate the mysterious institution. As they get closer to the truth, Sidney is forced to confront the conflict between his relationship with Amanda and his calling as a vicar, and the fact that he and Amanda must face her estranged husband Guy, but will it be together or apart?
Grantchester Season 3 Episode 1 airs on Sunday 23 April 2017 at 9.00pm on ITV.