March, 1939. Estelle is the headstrong daughter of Fleur, a Resistance legend who disappeared during the Great War. Only child Christa longs to break free from London suburbia, and fantasises about the Belgian heroine she believes saved her father. When Estelle comes looking for the truth about her mother, the two women become friends. Estelle invites Christa to De Eikenhoeve, her family's country estate, where Christa encounters Estelle's two brothers - brooding, tempestuous Robbe and dependable, golden-haired Pieter. During that long, hot summer, passions run high. When war breaks out Christa must return home, but not before she has done something she will regret for the rest of her life ...