Agatha Raisin and Love, Lies and Liquor by M. C. Beaton
Agatha Raisin thinks she's in for a treat when her old flame James Lacey invites her on a holiday, but to her horror, his idea of an exotic destination is a small, rundown town called Burryhill-on-Sea. Needless to say, the break doesn't go as planned. When a guest staying in the same hotel as Agatha and James is found murdered, Agatha quickly becomes prime suspect - and must solve this case from a prison cell!