Agatha Raisin and the Witch of Wyckhadden — M.C. Beaton

EYE OF NEWT, TOE OF FROG..AND MURDER

Left with bald patches thanks to the wicked doings of a murderer from a previous investigation, Agatha flees to Wyckhadden to grow her tresses back in privacy. When a local witch provides her with hair tonic (and a love potion for fun), Agatha's hair begins to sprout--but the witch is found bludgeoned to death. The odd elderly residents who inhabit Agatha's elegantly faded hotel seem innocuous on the surface. But as she delves into the killing, she turns up secrets best left undiscovered, and powerful motives for revenge. Balancing the amorous attentions of police inspector Jimmy Jessop with an ever-more treacherous search for the culprit, Agatha's at her wit's end--and ready to cast a spell of her own...