Emily Harris, recently divorced and returned to her hometown, renews her relationship with her exotic grandmother Eleanor, over the objections of her mother Elaine, with whom she has her own fraught relationship. Over time it transpires that Eleanor, arch and secretive, has a passion which she wishes to imbue in Emily?but Eleanor dies before the mystery is revealed in full. On her death, Eleanor leaves Emily an important clue: a small hand-loomed tapestry, possibly made by an ancestor.

In an act of abandon that shocks even herself, Emily seduces her childhood neighbor and nemesis, Carwyn. Fleeing to the Welsh Marches to sort out her motivations, she discovers a branch of the family kept secret by Eleanor for years. There she finds acceptance and help in unraveling Eleanor's mysterious passion, from her step-grandmother Viviane, as well as from Viviane's daughter Katti and her fianceé Helen. The appearance of Carwyn complicates matters; but it is with the aid of these four that Emily is able to find that the keys to the mystery lie with her own mother Elaine, and she must return home to come to terms with that relationship.