Christine Morris has been sent to Edinburgh to attend a conference on the latest in police methodology. There she is tracked down by the Northern Constabulary, Stornoway, Outer Hebrides, who inform her that her estranged mother has been involved in a vehicular homicide and has gone missing. Reluctantly, Christine agrees to fly up to Stornoway, where her mother was last seen. Her arrival is followed by the suspicious death of one of the islanders.
The story is really well written and keeps you guessing to the end with lots of twists and turns.