Season 11 Episode 01

Alphy has been waking from a recurring dream in which he prays over a dying person, and it leaves him with dread he cannot explain. Geordie tells him he wakes with dread every day. Geordie assumes the dream concerns Alphy's mother, Mira Kohli, whom Geordie tracked down at the end of Series 10. Alphy has met her several times since and calls her Mira rather than mother, and he has not asked why she left him at a foundling home or who his father was.

The village is staging an American-themed drive-in film fundraiser for Leonard's halfway house. Bert Mills, who owns a garage, has lent the cars. A local paper has printed Bert's obituary on the morning of the event. Bert arrives alive, laughs the notice off and wants no fuss, and his wife Miriam is unnerved and asks Alphy to have Geordie look into it. Betty, a waitress on roller skates, and her boyfriend Freddie, whom Bert sacked for lateness, are working the event, and Betty notices Miriam's ruby ring and says Freddie should buy her one. Bert argues publicly with the newspaper's editor, Gregory Parsons. During the film two figures are seen fighting behind the screen, a car then accelerates through the crowd driven by Freddie and stops, and Bert is dead in the back seat, his neck punctured by many small wounds. Freddie says he did not know Bert was in the car and that Bert was drunk and asked him to drive it home.

Geordie notices a tool kit in the boot but does not believe the tool in it is the weapon. At the newspaper office Parsons says Bert placed the obituary himself, and Parsons has written repeatedly that Bert is a con man. Miriam calls the articles lies and sends the police to the family accountant, Mr Switch, who vouches for Bert and produces a letter Bert told him to open only in dire circumstances. The letter blames that bastard hack for anything that happens to Bert. Parsons then confesses to the murder, and Larry reports that Freddie has confessed as well. Put in a room together, they both claim not to know each other and snipe at each other. The post-mortem shows no bruising to Bert's stomach, so he was not one of the two men seen fighting behind the screen, and both Parsons and Freddie have bruised stomachs. Freddie says Parsons pinched Betty, which started the fight, and that Parsons was having an affair with Miriam. Neither man can say what weapon killed Bert, and both have confessed to protect someone else.

Mira visits Grantchester for the first time and meets the household. The vicarage dinner is awkward, since Alphy has not provided a vegetarian dish, and Mrs Chapman's questions about Alphy's father drive Mira outside. She tells Alphy she lives alone in a village in Essex, works as a school secretary and keeps a grumpy cat, and that the church he has found is foreign to her because it is so white, and says all she wants is for him to be happy. Back inside she loosens her hat, and Alphy sees her hatpin. He and Geordie test a pin on an apple, and it makes the marks seen on Bert's neck.

Parsons's confession was protective. Bert had bought a fortieth-wedding-anniversary message about his love for Miriam, Parsons replaced it with the death notice out of jealousy, and he wanted Miriam to leave Bert. Miriam would not leave, and describes the affair as sex only.

The killer is Betty. She was also having an affair with Bert and believed he would leave Miriam for her. At the fundraiser, seeing Miriam's ruby ring, she asked Freddie to start a fight with Parsons as a distraction, got into the back of Bert's car, and stabbed him in the neck with a hatpin when he tried to kiss her. She told Freddie what she had done and he lied to protect her, and the blood on her apron was passed off as ketchup.

Alphy finally asks Mira why she gave him up. She was fifteen, his father was sixteen and disappeared when she told him she was pregnant, she told no one else, gave birth alone in her room and in silence so her parents would not hear, and left the baby at the nearest place that would take him. Because it was a Christian home, nobody in her own community would trace the child to her. Alphy is left upset rather than relieved, since he had believed his being placed there meant his mother had wanted him to be a priest, and it was happenstance. Geordie introduces Mr Switch to Cathy and Mrs Chapman, whose accounts at CeCe's Boutique have been causing arguments, and Switch's arrival settles the immediate squabbling. Mira says she would like to visit again despite the lunch.

The episode hides its weapon in plain sight from the first scene, since the hatpin that a woman loosens is the object that kills, and the answer arrives when a different woman with a different hatpin solves the case. The stomach bruising is the detail that rules out both confessions, because neither man could have been the figure behind the screen and the man who died has no marks on him at all. Mira's account of giving birth in silence is the hardest scene in Series 11, and the reveal that Alphy's vocation was an accident rather than an inheritance is the best thing the series does with him.