The witches' tree / M. C. Beaton.

Cotswolds inhabitants are used to inclement weather, but the night sky is especially foggy as Rory and Molly Devere, the new vicar and his wife, drive slowly home from a dinner party in their village of Sumpton Harcourt. They strain to see the road ahead--and then suddenly brake, screeching to a halt. Right in front of them, aglow in the headlights, a body hangs from a gnarled tree at the edge of town. Margaret Darby, an elderly spinster, has been murdered--and the villagers are bewildered as to who would commit such a crime. Agatha Raisin rises to the occasion (a little glad for the excitement, to tell the truth, after a long run of lost cats and divorces on the books). But Sumpton Harcourt is a small and private village, she finds--a place that poses more questions than answers. And when two more murders follow the first, Agatha begins to fear for her reputation--and even her life. That the village has its own coven of witches certainly doesn't make her feel any better...