"The Killings at Badger’s Drift" by Caroline Graham

An audio book set in 1987.

Miss Emily Simpson (80) sees 2 people having sex in the woods. Later when she's at home she phones the Samaritans. There's a knock at the door. Next day she's found dead. Her friend Lucy (also a spinster) is suspicious (she reads whodunnits) and goes to the police.

Detective Tom Barnaby (who likes gardening) has a wife who does AmDram but can't cook, a daughter Cully who's at Cambridge doing a degree, and a colleague Troy. Because there are doubts about the professionalism of the local doctor (Trevor Lessitor), Barnaby gets a PM done and finds Simpson died of Hemlock poisoning

Barbara Lessitor, 40+, is pretty. She began shoplifting make-up and clothes when 15. While a virgin, she attracted a boss at work who got her pregnant. When he gave her money to get an abortion she left her job and become an escort. Then she found a widower, Trevor Lessitor, in a supermarket. They married, but Barbara has never been liked by Judy, Lessitor's plump daughter. Barbara is having an affair and for some reason needs £5k.

Catherine Lacey, pretty, is about to marry Henry Trace - a wheelchaired widower who owns a farm. Her brother is Michael, an artist (who Henry's supporting? Who Judy fancies?). The farm manager is attractive David Whiteley, separated, with a son he's not seen for a while. Phyllis is the live-in house-maid (and sister of Henry's first wife), who'll have to leave. Henry's first wife died in a shooting accident. Barnaby researches into it. Michael was one of the beaters. Denis is gay - his mother's nosy.

Trevor frequents an up-market brothel because his wife doesn't like having sex with him.

Denis's mother is violently killed. She's been keeping notes about goings on and has been blackmailing people. Phyllis is arrested for the death of Henry's first wife. She confesses (she wanted Henry), and is found dead in the night in a police cell. A bloody knife is found in Michael's house. He's arrested too. He says he sketched Judy for 2 hours when the 2nd murder happened, and the knife was planted. Barbara admits to having an affair with Whiteley (whose wife says is violent and over-sexed). Trevor says she can stay if she submits to his conditions. She rejects his offer.

In the end Michael and Catherine are the guilty ones. They were in an incestuous affair. Tom debriefs to Lucy.

Other reviews

• mysteriesahoy (The heart of the novel though has to be the mystery and I am disappointed to say that in this respect I found the book a little lacking. ... Too much hinges on discoveries about personal lives, while our understanding of the case itself felt a little static.)
• Cat Eldridge ([the characters] feel like simple and not terribly interesting plot devices, not real beings. ... Kudos to the TV series’ writers for changing Barnaby and Troy from less than appealing characters into individuals worth knowing!)