Grantchester airs Sundays at 8:00 pm and is available to stream. Recap the previous and following episodes and other seasons.
Geordie needs Will’s help with a case. No, it’s not a murder—just Will’s stepsister Tamara, who has been brought in for dining and dashing as well as stealing a fancy napkin ring. She refuses to be searched, even at Will’s less-than-enthusiastic urging, and so has to stay at the police station.
But then a murder investigation opens up while Will is at the station. Three servicemen and a lieutenant from the nearby American airbase have been brought in for trespassing at a quarry to race cars. Larry has arrested them all, but the lieutenant insists that he will discipline his subordinates—he was doing so when he found them at the quarry. Geordie, an admirer of military authority, apologizes to the lieutenant.
But when Geordie’s assistant Miss Scott offers one of them tea, he collapses. He’s dead.
One of his companions, Bobby, panics: he and his dead comrade, Stanley, had plans for after the service. They and Stan’s brother Mikey were all going to buy houses in a row. Howie is calmer and more resigned.
The pathologist can’t make it in until the morning, so Geordie and Will examine Stan’s body themselves. Geordie wants to learn the truth of the matter before morning, when the American military is sure to take over and hide everything on their base. Stanley has pills in his pocket as well as some stuck in the back of his throat. The insides of his arms are also marked by cuts, and there’s a strangulation bruise on his neck.
Geordie recalls that Stan was carried into the station by Howie and Bobby—he was probably already dead, and they were just trying to get out before anyone noticed. The pills are misdirection—and Bobby is a medical orderly who takes pills for his stomach.
A broken necklace is discovered in the back of the police van in which the men were transported. A tag from it reads “OW.” The lieutenant says there was a commotion in the van while the other two “dealt with” Stan. He tried to stop it and couldn’t see because it was dark.
Geordie doesn’t think the lieutenant is who he says he is: he said he had to pull Stan into the van, despite the fact that officers always get into a vehicle last. A call to the airbase confirms the real lieutenant is in bed with the flu. Geordie finds the fake lieutenant trying to break a window in the bathroom to escape.
This whole exchange also leads Will to admit that he was exempt from serving in the military, upsetting Geordie, who was in a Burmese prison camp and admires the fraternity and duty of military service. He insists that Will deal with Tamara so that Geordie can have his office back from her.
She is at first insouciant, but after Will says he was trying to cheer up an increasingly depressed Leonard when he was forced to come help her, she apologizes and hugs him. She also finally submits to a search by Miss Scott, and is allowed to leave when nothing is found.
Will has at least asked Daniel to visit Leonard, who is drinking, smoking, listening to jazz, and lashing out at Mrs. C as he contemplates his impending trial. Leonard tries to end things; he’s about to be disgraced in front of everyone, and Daniel seems immune to shame.
Daniel walks out. If you think I’ve never felt shame, you don’t know me, he tells Leonard when he follows. Daniel was married, and Leonard knows nothing of his past. His wife found a letter he had written to a man and broke off their relationship—a scandal, given that she was pregnant. She had a miscarriage, and Daniel has always blamed himself. He was cast out from his town; he wasn’t even welcome at his own mother’s funeral.
Leonard apologizes to Daniel, who confesses that he only felt he could start his life anew and be hopeful again when he met Leonard. Leonard realizes that Daniel also has everything to lose in the trial. He turns up the music, and the two of them dance together in the starlit back yard.
Geordie considers Will a disgrace, for having bought his way out of military duty. He tells Will to go home, but first Will reveals that a notebook of what the police thought were the servicemen’s racing records is actually a coded black market inventory. He also notices fluid under the fake lieutenant’s car: his brakes were cut.
Who is the lieutenant? Geordie has Cathy bring him old Christmas cards: he always receives one from the commander of the American airbase. Finding it, he realizes the lieutenant is the commander’s son, Orson Wade. The necklace is his.
Geordie apologizes to Will, who explains that his father made the arrangements for him to avoid military duty, and that he regrets it.
Orson admits to failing the pilot exam twice; he pretends to be a lieutenant in town to live up to his father’s expectations. He, Howie, and Bobby are all outsiders who found themselves under Stan’s influence, but Stan was a brutal leader, forcing them to do stunts and sell things on the black market. He made Mikey try to jump the ravine in a heavy car, knowing it wouldn’t work, and Mikey was killed. Orson’s necklace broke in the back of the van when Howie and Bobby took their revenge on Stan, killing him, and Orson tried to intervene.
What about the cut brakes on Orson’s car? Stan’s uniform has brake fluid on it. Geordie also realizes the necklace tag could read “MO” instead of “OW”—for Mikey Obrero, Stan’s late brother. Orson was the cruel manipulator, not Stan—Stan tried to kill Orson by cutting his brakes for leading Mikey to his death. Further confirmation comes from the scars on Bobby’s and Howie’s arms—punishment meted out by Orson to them and Stan. Knowing that the cut brakes would be discovered at the police station, Stan attacked Orson in the back of the police van. Bobby intervened and accidentally choked Stan to death.
Bobby will be tried for manslaughter under military law, while both Stan and Mikey are dead because of Orson—but he’ll get off free. Until Geordie steps in and charges him with the murder of Mikey. Orson is a civilian, so he can’t be tried—or protected—under military law.
Will and Geordie finally leave the station for their homes. In his pocket, Will discovers a fancy napkin ring. Turns out Tamara did take it, after all.