The most complex of McDermid's books I've read to date, I think. I was struck as I read it by a sense of familiarity - then realized that I had watched most of it when it was televised on PBS's Masterpiece Contemporary only a month or so before.
The story is told through two timelines - the early 1960s, when a young woman disappears and the investigating officer becomes obsessed with finding out what happened to her, and nearly 40 years later when a journalist (who has ties of her own to the young woman's home town) decides to write about the decades-old "cold case" and uncovers an even deeper mystery. McDermid skillfully drops subtle hints throughout, but the ultimate resolution surprised me. The English village setting is anything but bucolic, with a host of suspicious, resentful, and hostile locals populating both timeframes.
McDermid has created several mystery series, but this one stands alone, and is understandably considered one of her best.