Season 05 Episode 06

Will, still drunk from the previous night, goes to a party at his mother's house and meets St John's son Clement, whom he drinks with and whose request for different music he relays to the band. Amelia tells him to stop. Geordie finds Matthew Butler, now homeless, in a cheap hotel and pays for his room.

In the morning Geordie and Larry find the body of a woman, Nora Martin, on Jesus Green. She has been stabbed and laid out in the shape of a crucifix and is wearing a wedding ring, which points to a marriage to God. She has a marriage certificate with her. At the morgue Larry reports that the blade broke off in her and stayed there, and the ring identifies her as a nun of the Order of St Beatrice. Her husband, Frank Martin, and her son, Robin, are told. Frank says his wife disappeared five years ago and did not take her wedding ring with her, and the file records a probable drowning.

At the convent, Sister Michael, also called Lavinia, admits them to the office of Sister Grace, who has already concluded Nora is dead because she is the only sister unaccounted for. Grace shows no emotion and does not know where Nora went, and her room contains a suitcase. The file holds a second missing-persons report, for Lavinia Jones, from the same year, and another, and the picture is of women reported missing over five years who are all inside the convent.

Will meets Clement again at the party. Leonard's father, Russell Finch, arrives in Grantchester, refuses to enter the church and waits in the pub. He drinks through his conversations with his son, talks about their old landlord Gideon rather than Leonard's mother, and remembers a fishing trip as a happy occasion that Leonard remembers differently. Will and Geordie return to the convent and find Grace out of uniform with a small girl, Hattie, on her lap. The nuns are taken to the station and matched with their families, and Hattie is identified as Nora's daughter. Grace denies killing Nora, and tells Will he sees a prison where there is not one, and that this says more about him than about her. Will accuses her of refusing to let Nora leave, and Hattie is returned to Frank and Robin. Lavinia is found in the police station lobby with a bloodied face.

Will and Leonard, thinking Hattie is being harmed at home, go to the Martin house, where she is fine. Geordie notices a newly replaced rug, and under it blood. Frank Martin admits stabbing his wife once, after seeing her in the street and bringing her home for an argument, and Geordie points out Nora was stabbed repeatedly.

Will apologises to Grace for misjudging her, and she explains that she had been looking after women who had nowhere else to go. They talk, and embrace and kiss and spend the night together, and he later tells Geordie that it was Grace rather than Ellie. Leonard confronts his father. Russell belittles him in the vicarage, and Leonard tells him to write to his employers about his sexuality at once, that he does not care, that he is in love with a man, and that he will not be ashamed, and says he feels sorry for him. Sylvia, who hears the end of it, tells Leonard nothing Russell said is true. Will goes to Amelia and tells her he is afraid she will be trapped in a marriage with St John as she was with his father, but that it is her decision, and he asks them both for money for the gym. Will finds Matthew, apologises for turning his back on him, and gives him the keys to the gym. The season closes with Will's birthday party, Daniel invited by Sylvia, and Will and Geordie drinking outside, where Will says he lost his sense of wonder after what happened with Vic and has accepted that things cannot be perfect.

The finale is the strongest of Series 5, because the convent holds five years of missing women who were never missing, and the one who did leave was killed by her husband and laid on the grass in the shape of a cross. The rug is where the case turns, and it turns on a police officer noticing the floor. Russell Finch's visit pays off the thread the series has run since his first mention, and the confrontation in the vicarage is the best scene Leonard is given. The year ends with the two central figures drinking outside a birthday party.