Season 01 Episode 05

Sidney takes Geordie to London for a night off, to Straight 8's, the jazz club run by Archie Johnson, the father of Jennifer's boyfriend Johnny. Outside, Walter Stirling is thrown out by the doorman, Tommy. Inside, Sidney and Geordie meet Jennifer and Johnny and hear the singer Gloria Dee. Geordie, whose taste is Gilbert and Sullivan, is unimpressed at first. Amanda arrives alone. Geordie sees DCI Jacob Williams of the Metropolitan Police being handed money by Archie. Claudette Johnson, Johnny's sister, is found dead in the alley behind the club with her head stoved in by an industrial counterweight, her body covered with her father's coat. Williams takes charge of the case, is dismissive of Geordie's Cambridgeshire force, and is plainly on terms with Archie.

Sidney works out that Claudette had a boyfriend her father would not have accepted, Walter Stirling, a black man who had been a student teacher, and that Jennifer had covered for her by putting on Claudette's uniform and checking coats so that Claudette could slip out. Claudette's message to her brother, remember what Mum used to say, turns out to be about the two of them having each other. At the funeral Johnny accuses his father of having beaten their mother, and says Claudette was running away. The case has a second layer, because a bouncer, Tommy, gives Geordie a name and a date: Charlie Rush, a man murdered years earlier who had been having an affair with Johnny and Claudette's mother. Archie Johnson was the prime suspect and was cleared, and Williams is the officer who cleared him.

The killer is Justin, Archie's long-serving right-hand man at the club, who is the son of Charlie Rush. He killed Claudette with the same weapon that killed his father, and he is holding Archie hostage in a warehouse when Sidney finds them. Sidney talks him into putting the gun down, Justin is arrested, and Archie admits to the murder of Charlie Rush. Williams wants the confession ignored and Geordie tells him he will go to Williams's governor if he does. The club reopens as Johnny's Place.

The episode's other business is Sidney's own conduct. He sleeps with Gloria Dee and finds one of Claudette's bracelet charms under her bed, which she explains by having lent her room to Claudette and Walter. He destroys his jazz records afterwards. Hildegard, who has bought him a Gloria Dee record, notices that he has changed since London. Mrs Maguire ends the episode by telling him that Hildegard has fallen in love with him, and the audience knows he has not told her what he did.

The episode is the one in which the series leaves Grantchester and takes its chances in a different city and a different musical register, and it is the strongest of the first series because the two plots, a killing and an old murder, meet in the same man. The police corruption is played straight, with a Met officer taking money in front of a visiting detective and then clearing the man who paid him, and the confrontation in the warehouse is resolved by a vicar who knows the family rather than by an arrest.