Christie's best (and best known) works were written in the 1930s and 40s, when socialites and servants and down-on-their-luck aristocrats were in their escapist heyday. Dame Agatha was clearly of the old school and didn't seem to 'get' the 60s and while her skills remained sharp, her material didn't seem to fit. The Pale Horse is one of her better late-era works, possibly because (as we've learned from Mad Men) the early 60s were more like the 50s than the wild world into which I was born. Academic Mark Easterbrook has taken a flat in bohemian, beatnik Chelsea while writing a book on Mogul architecture. Fighting writer's block and an empty refrigerator, he wanders into a Soho cafe and a fight between two wealthy girls 'slumming it' in dirty clothes and with unsuitable boyfriends. Thomasina (Tommy) Tucker loses the fight - and two handfuls of hair - but wins the boy, and two weeks later Easterbrook reads her obituary.
A few nights later, a priest who has just heard a dying woman's confession walks into another cafe, writes a list of names, and is murdered as he walks home. Police Surgeon Jim Corrigan notices his name, and the name of at least one recently deceased person - Mark Easterbrook's aunt, Lady Hesketh-Dubois. Corrigan and Easterbrook knew each other at university, so they discuss the list over coffee, and Easterbrook identifies another 'victim' - Tommy Tucker. Everyone on the list had people (mostly expectant heirs) who benefited from their deaths, but everyone on the list died from natural causes with the beneficiaries hundreds if not thousands of miles away, so how can this be murder?
Well, this is a Christie novel, so of course it's murder. Murder by remote control, courtesy of three witches who hold seances at a former inn called The Pale Horse. Coincidence, a friend's dim and ditzy girlfriend Poppy, and a request to bring Ariadne Oliver to a church fete bring Mark to The Pale Horse and into the acquaintance of art restorer Ginger Corrigan. Ginger and Mrs. Dane Calthrop, the vicar's wife (this is a Christie novel, so there has to be a distracted vicar with a down-to-earth wife) are the only people who agree with Mark that something evil is happening at The Pale Horse, so they set a trap with Ginger as the bait. As her health mysteriously fails, Mark tries desperately to solve the mystery. A comment about hair from Mrs. Oliver and seeing his cousin medicate a dog save Ginger (and, it turns out, at least three real life thallium poisoning victims, saved by medical staff who'd recently read The Pale Horse), and a discussion with an old schoolmate of Poppy's eventually reveals the 'who' and 'why' with just enough evidence against an innocent man to fit the Christie mold.