In a Sussex town on the south coast of England, a widely disliked art teacher at a posh private girls' school disappears without explanation. None of her students miss her boring lessons, especially since her replacement is a devilishly hunky male teacher with a fancy car. But then her name shows up on a police missing-persons list. What happened to Miss Gibbon, and why does no one seem to care?

Meanwhile, detective Peter Diamond finds himself in Sussex, much against his wishes. His irritating and often obtuse supervisor, Assistant Chief Constable Georgina Dallymore, has made Diamond accompany her on a home-office internal investigation. A Sussex detective has been suspended for failing to link the DNA evidence of a relative to a seven-year-old murder case - a bad breach of ethics. Diamond is less than thrilled to be heading out on a road trip with his boss to investigate a fellow officer, but he becomes much more interested in the case when he realizes who the suspended officer is - an old friend and not a person he knows to make mistakes.

As Diamond asks questions, he begins to notice unsettling connections between the cold case and the missing art teacher. Could the two mysteries be connected? How many other area disappearances have gone unnoticed and uninvestigated? Diamond and his hapless supervisor have stumbled into a web of related crimes. Will Diamond be able to disentangle them?