Season 11 Episode 07

The vicarage and Alphy are in a state. Bottles, glasses and dirty plates are everywhere, and Alphy leaves in the middle of his own sermon. He goes to the London park where he last saw his mother and confronts her. He tells her she has turned his life upside down and that he is no longer sure he should be a vicar, and Mira replies that he invited her into his life and that it changed hers for the better, that she is proud of how kind he is and sorry for how she has treated him. She says she wants her family to meet him, in time, and that he does not need her because he has a calling in which he helps people and a family of sorts in Grantchester.

Alphy goes to the police station to apologise to Geordie and finds him drinking. He tells Geordie he is glad Geordie found his mother, and Geordie forgives him. It is Geordie's last week on cases before he moves to the new post, and he says he is glad of it for Cathy's sake. He believes Cathy is having an affair with Peter Switch and says he has no right to confront her because of his own affair years earlier, and Alphy tells him to tell Cathy what he knows and put it right. Cathy has not yet done anything with Switch, though she has overcome her reluctance to go to London with him for a fashion show and to stay the night, and Mrs Chapman refuses to babysit. The argument is cut short when two men come into CeCe's Boutique, lock the door and draw the curtains.

Four masked men have carried out a series of armed robberies over recent weeks, and Geordie thinks he has identified one of them when a man is found dead in his van. Frank Brook is a florist. He is found in the driver's seat, with blood on the outside door handle, blood on the stems of a bouquet of roses in the back with an anonymous note apologising to a lover for ending things, and a toolbox holding a sawn-off shotgun and a balaclava. Frank's fiancee Susan is not surprised to hear he is dead, which strengthens the view that he was one of the robbers, though she will not confirm it at first, and she eventually gives the names of the others: Bob Spindlove, JP Millwood and Dexter Sutton. Bob was arrested the night before and used his telephone call to contact Frank, so Frank knew the police were closing in.

Larry discovers that Switch was also Frank's accountant. Geordie telephones CeCe's and gets no answer, and he and Alphy drive over. They see JP and Dexter leaving by the back door and recognise them, the two men go back inside, and JP returns holding a gun on Cathy. JP and Dexter are the robbers inside the shop. There is little money in the till because a bank run has just been made, and they are waiting for a larger sum from Switch, who has been holding the money Frank's gang stole in CeCe's bank account to hide it. Cathy is disgusted with herself for trusting Switch and admits she made him a signatory on the account without telling Mrs Chapman, and that she thought CeCe's was succeeding when in fact it was barely scraping by. JP and Dexter wait for Switch to arrive so they can withdraw the money with him at the bank, and Cathy and Mrs Chapman refuse to do it themselves. A customer, Tracey, comes out of a changing room and is made to wait with them, and Mrs Chapman, who knew JP's late mother, confronts him about her disapproval, and he says he is doing this for his daughter.

Switch arrives and Dexter takes him to the bank, and they return with the money as Geordie and Alphy arrive. Dexter and JP had been waiting for Frank so that all of them could flee, and Frank is not coming. The hostage situation begins, and as the police surround the shop JP stops Dexter attacking Switch with a knife and takes over the negotiation, asking Geordie for food and a fast car in exchange for two of the four hostages, with the last two to be released after they leave town. Geordie arranges for Alphy's car to be run almost dry and for the fuel gauge to be altered so that it still reads full. While Jack goes to fetch it, Mrs Chapman has a panic attack and JP asks for a doctor, Alphy offers himself in exchange for her and JP accepts, Mrs Chapman is released and recovers and tells Geordie about JP's daughter.

Geordie's working theory is that the flowers and the note were from Frank to Susan, telling her he was leaving without her, and that Frank and JP were heard arguing in a pub the night before, perhaps because Frank wanted JP to abandon his daughter too. When Alphy tells JP that Frank is dead, JP is shocked. Frank was killed with a knife and Dexter has a knife, so JP turns on Dexter and the gun goes off during the struggle. Nobody is hit, Dexter takes the gun and sends JP out to explain matters to Geordie. JP has four tickets to leave the country and wants to keep one hostage until he is away, and when Alphy offers, Tracey takes his place, wincing when Cathy takes her hand in thanks. The number of tickets is the first clue, since with Bob in jail the fourth ticket was meant for Susan, so Frank was not abandoning her, and Geordie starts to wonder whether Frank had other lovers. Susan finally admits he did and gives one name: a girl who worked with him at the florist, who lived near where Frank's body was found. Her name is Tracey.

Inside CeCe's, Alphy has reached the same conclusion. There is pollen on Tracey's dress and her hand is bleeding from rose stems, so the bouquet Frank left was for her. She pulls a knife on Dexter and takes the gun. Frank had promised her a life of luxury and was going to leave her behind, but she still wants the money she believed was coming to her. She makes Dexter carry the money out at gunpoint, followed by the hostages and then JP. Outside, Dexter throws down the money, takes the gun back from Tracey, and the police arrest Tracey and JP. Geordie tries to talk Dexter into surrendering, and Dexter shoots him in the stomach and runs. Cathy and Alphy reach Geordie as he bleeds, and Cathy tells him she loves him and that she is not losing him.

The second thread is Leonard and Daniel's move towards Raymond. They have become like uncles to him, and Mrs Chapman warns Leonard that a gay couple raising a child will not end well. Leonard is offended and Daniel accepts that she has a point. When Marcus objects to Raymond going into social services, Daniel reverses his position, and Raymond cannot be adopted by Leonard because Leonard has a criminal record, while Daniel has none.

The episode is a siege and it is also the moment the series' two longest-running arrangements collapse at once, since the shop is held by men who were robbing it because an accountant hid the money there, and the accountant is the man the shop's owner trusted. The fuel gauge is the ruse that gets the first hostage out, and the fourth train ticket is the detail that turns a murdered robber into a murderer's victim. Tracey's bleeding hand is the clue that solves it from inside the shop, and the episode ends with a policeman bleeding on the pavement and the boy who shot him running.