If you haven't yet read Agatha Raisin and the Wizard of Evesham, you should read that book before starting this one. There's a continuity of story line that adds to the appeal of Agatha Raisin and the Witch of Wyckhadden.
At the end of Agatha Raisin and the Wizard of Evesham, Agatha is having the ultimate bad hair day as she has lost most of hers. Not wanting her former fiancé, James Lacey, to see her looking like that, Agatha flees Carsely for a spot on the south coast of England in Wyckhadden during winter. She soon finds that neither the weather nor the wintry attitudes of her fellow guests at the Garden Hotel suit her fancy. With her hair firmly covered by a wig and scarves, Agatha does venture out when a nice-looking man invites her dancing.
Concerned about her hair, Agatha is soon persuaded to visit the local witch, who offers many remedies that often seem to work. Having bought some hair potion, Agatha decides it won't hurt to buy a bottle of love potion while she's there.
Pretty soon, Agatha's hair is growing in again, she seems to be having success with the love potion, but Wyckhadden and its residents are getting on her nerves. Uncharacteristically erratic, Agatha gets into lots of trouble by lying to the police . . . which causes great problems when dead bodies start turning up. No one takes her very seriously as a sleuth, and even Agatha begins to suspect that she's no more than a pushy blunderer whose ineptness triggers violent solutions to crimes.
In this book, M. C. Beaton is determined to convince readers that Agatha's many fears (of aging, being alone, losing James Lacey, not being the center of attention, losing a friend, and not having something to do) are destroying her chances for happiness. I think you'll agree with M. C. Beaton.
But Agatha's self-sabotaging behavior gets to be more than a little annoying in this book, making Agatha Raisin and the Witch of Wyckhadden one of the weakest entries in this generally entertaining series. Unless you feel compelled to read all of the novels in this series, you could certainly skip this one. You probably won't find the plot to be all that interesting; the new characters among the suspects and victims aren't likely to enlist your sympathy; and the mysteries aren't particularly rewarding either.