It's a euthanasia novel--no, it's a Diane Gabaldon Highlander time travel novel--no, it's a study of how infidelity impacts a marriage. Yes, it's all three, and like the 3 or 4 other Picoult novels I have read, it's a combination of Lifestyle Cable issue of the month and whatever literary style is popular at the time. When a clansman euthanizes his ailing wife and brings her body to his highland chieftain in Massachusetts (in the modern world, the chief is a police chief), he must both defend and prosecute the man. The issues are complicated when his wife, a florist, goes to work for the defense, and when he falls in love with her new employee. Although the "good" people in Picoult novels are tidy souls, there is a clutter of sub-themes in "Mercy"--water-witching, the language of flowers, tree pruning, the Glencoe massacre in 17th-century Scotland. Having travelled to Glencoe in the seventies and having heard people speak of it like it had happened yesterday, I can just imagine that Campbells and Macdonalds might be influencing the events of modern day New England--but it's a stretch.