Casilda Montero is the beautiful and hot-blooded daughter of a wealthy Spanish aristocrat. Sent from the family hacienda in Southern Spain to an English boarding school, she befriends Joscelin Howard, a shy, serious English girl. As both girls find themselves swept up in the dramatic events unfolding in 1930s Europe, this enduring friendship is the one constant in their lives. From the carefree glamour of London high society to the devastation of the battlefields in Spain, Casilda, Joscelin and their families are tragically linked by passion and bloodshed.