Chigton Green looks like an idyllic British village, with its quaint shops, popular aristocratic family, and everybody-knows-everybody air, but distrust seethes beneath the picturesque surface. When the Creswells, who own the chocolate factory that provides work to many of the villagers, go for a hunt, the family scion’s horse is lamed. He takes his son Rupert’s horse instead, but later that afternoon the horse returns to the family estate, bloodstained and missing its rider. The Creswell patriarch’s body is found in the fields, with a shotgun blast to the head.
Farmer Bell was seen in those parts with a shotgun, so Morse and the local constable head to his home. There they find his wife, Mandy Jane, dead in the yard from a shotgun and Bell himself sprawled in his room, having shot himself. Bell was a bit of a brawler when drunk, but the constable didn’t think him capable of a double murder and suicide. But there’s a type-written note in his jacket pocket alleging that Mandy Jane, who worked part-time at the Creswell factory, was sleeping with the now-dead Creswell patriarch. Attached to the note is a “Happy Families” card – every box of Creswell’s comes with one, each depicting a caricature of a different villager.
Similar “poison pen” letters have been appearing in Chigton Green for the past few months, all postmarked from Oxford. The greengrocer was the first to receive one, alleging that her mother died as a result of bad fish sold by the fishmonger (it was actually natural causes). Creswell’s human resources director has received a few, alleging an affair between the constable and Mandy Jane – they dated long ago – as well as one about Isla Fairford, the daughter of the village veterinarian. Isla and her father tell people she’s a single mom because she was widowed, but her son’s father actually left her for another woman – the letter revealed the truth.
The HR director also relates an incident from the Creswell Christmas party involving Mandy Jane: after having a bit too much to drink she insulted Sarah Clamp, the daughter of the greengrocer and fiancée of Rupert Creswell, and threw a drink in her face.
Sarah also has a connection to another person who turns up dead: Rufus Burrough, a reserved research fellow at Oxford. Sarah’s family raised Rufus, her cousin, after his mother moved to Australia. Now he has committed suicide in his bathtub. A burnt letter and what might be a Happy Families card is found in his fireplace.
Despite their connections, all of these deaths have seemingly simple explanations, and DCI Box and his henchman Jago are ready to close the cases. They’re also not too interested in a series of deaths resulting from a supply of heroin laced with quinine, an epidemic in which Strange has taken an interest. Strange suggests to Morse that Box’s investigation into the drug deaths has stalled for a reason, something borne out by Thursday’s observance of Jago surreptitiously picking up a package near a shop Thursday has been watching as part of his own investigation.
Box reveals his moral character when he tries to hand over a wad of money to Thursday for being loyal. After anguished deliberation, Thursday takes it – perhaps driven away from his ideals by the increasing distance between him and his wife Win, who hasn’t forgiven Thursday for losing their retirement savings by loaning money to his unscrupulous brother.
Morse makes his own ill-advised decision by asking Isla Fairford out for a drink, even though she is involved in an ongoing investigation. When Thursday finds out, he reprimands Morse, who in turn questions Thursday’s behavior. Morse later sees Thursday out drinking with Box and Jago; Morse’s mentor is becoming increasingly distant.
Jago and Box’s belief that the cases are closed is proven false when Murray Creswell is found dead in a vat of chocolate at the Creswell’s factory. He took a phone call before leaving the house late at night. He died of a circular wound that could be a gunshot – but Morse realizes it’s a very specific type of gun. Having watched Isla’s veterinarian father put down the Creswells’ lame horse, he recognizes the wound as from a horse gun.
When the police visit the vet, he discovers that his horse gun is missing from the locked box in his car where he keeps it. He was called out to an unusual address late the previous night, when Murray was killed, but he never found the house and eventually returned home. He was unable to get in touch with Isla, who had taken the original call, because she was on the phone all night with an old school friend, and the caller didn’t leave a number anyway.
Morse decides to peek around the Creswell factory again and sees a letter in a typewriter in the HR director’s office. She’s the anonymous Miss Ling, an advice columnist for Oxford’s paper. When she walks in on Morse in her office, she admits the truth and tells him the only other person who deduced her identity was Mandy Jane – Mandy Jane was obsessed with trying to guess the identities of people who wrote in to the column.
Morse returns to the Bell home and finds one of Miss Ling‘s columns pinned up. It helps him discover who has been sending the poison pen letters, and his hunch is corroborated by phone records that show who called Murray Creswell just before he was killed.
Thursday and Morse show up at the suspect’s house, and she hands them another poison pen letter that she has just received, about Sarah Clamp. But Morse and Thursday see through it as a fake. Isla is the one behind the letters. She had written in to Miss Ling to ask how to deal with being a single mother and save her son from stigma, and the columnist advised her to say she was widowed – this was the column pinned up at the Bell’s home. Mandy Jane had guessed the truth and also deduced from the column who the father was: Murray Creswell. Mandy Jane confronted Murray and blackmailed him for money.
Isla, fed up with the village’s malicious gossip, began writing the poison pen letters, sending them to her friend Rufus in Oxford to mail so as to avoid suspicion. She took revenge on Mandy Jane with her letter to Farmer Bell, who was unhinged enough that he flew off the rails and killed Creswell, Mandy Jane, and himself. Rufus committed suicide out of guilt for having caused deaths.
After Mandy Jane guessed that Murray was Isla’s son’s father, Murray began taking an interest in his son’s life, despite wanting nothing to do with him when he was born. He wanted Isla to admit he was the father so that he could give his son a comfortable life. This insulted Isla so much that she called him, asking him to come to the factory, and killed him. She sent her father off on a fake house call and left the phone off the line so that he got a busy signal when he called for more information.
That case solved, Morse gets a possible lead on a long-simmering investigation. Bright calls Morse specifically to a car crash. A spent round was found under the seat and a gun in the trunk – and Dr. DeBryn thinks they match the caliber that killed Fancy.