Kissing Christmas Goodbye by M.C. Beaton

It's October and Agatha Raisin longs for some excitement in her life. Her detective agency has been taking on the usual cases of lost pets and cheating spouses. She decides to start planning a spectacular Christmas party and to invite her ex-husband, James Lacey. Agatha then hires teenager Toni Gilmour as a new detective in her firm and gets a letter from senior citizen Phyllis Tamworthy saying that someone in her family is trying to kill her. She takes Mrs Tamworthy's case herself, traveling to the village of Lower Tapor (which Mrs Tamworthy owns, in addition to a large manor house). When she's poisoned by hemlock in her salad, there are loads of suspects ranging from her children (whom she was cutting out of her will) to the villagers (who feared for their livelihoods if Mrs Tamworthy went through with her plans to build a technical college on her land). Agatha is determined to find the murderer even though the police tell her to butt out, as usual. The Agatha Raisin books are still one of my favorite mystery series. I always look forward to the new one.