Set in 1970s Edinburgh, Tessa — born into a wealthy family but chronically overlooked — has a secret kleptomania: she only steals from people who mistreat her. Gideon, a sharp-eyed police consultant, moves in as her new tenant and coincidentally takes charge of the very thefts she committed. Amid cat-and-mouse probing and tension, they are drawn into family strife, overseas drama and royal intrigue, as a quiet affection grows between them.