Agatha Raisin and the Wizard of Evesham (Agatha Raisin Series #8)

The curmudgeonly yet irresistible Agatha Raisin finds herself addicted to Mr. John, her wizard of a hairdresser, after a home dye-job ruins her hair. And when the hairdresser dies in the middle of his shop on a busy Saturday, it is discovered that his vitamins were laced with a rare poison. Agatha must, of course, investigate!