Sepulchre, Kate Mosse

1891.  Seventeen-year-old Leonie Vernier and her brother abandon Paris for the sanctuary of their aunt's isolated country house near Carcassonne, the Domaine de la Cade.  But Leonie stumbles across a ruined sepulchre - and a timeless mystery whose traces are written in blood. 

2007.  Meredith Martin arrives at the Domain de la Cade to research a biography.  But Meredith is also seeking the key to her own complex legacy and becomes immersed in the story of tragic love, a missing girl, a unique deck of tarot cards and the strange events of one cataclysmic night a century ago. . .