The indestructible Agatha Raisin, still at the top of her game in her darkly droll 17th whodunit (after Love, Lies and Liquor
), is feeling woefully middle-aged after hiring Toni Gilmour, an endearing U.K.-style Nancy Drew full of teen energy and charm. As Toni takes over the pet recovery end of the sleuthing business, Agatha looks into a mysterious letter from Phyllis Tamworthy, the rich matriarch of the Manor House in the idyllic Cotswolds, who suspects family members of plotting to kill her before she can change her will to disinherit them. Agatha and her friend Sir Charles Fraith attend Phyllis's 80th birthday party, only to see the lady keel over, poisoned by hemlock in her salad. Digging into Phyllis's past yields an even darker mystery. Bestseller Beaton's dry wit enhances Agatha's struggles with aging, men and her most challenging case yet. (Oct.)