The Memory Stones by Caroline Brothers
Buenos Aires, 1976. Osvaldo Ferrero, a distinguished doctor, and his wife Yolanda escape the city with their daughters, sensible Julieta and wilful Graciela, who is nineteen and madly in love. On their return, the Argentine military stages a coup. Friends disappear overnight, and Osvaldo is forced to flee to Europe. When her fiance is abducted, Graciela goes into hiding, then she vanishes in turn. As Yolanda fights on the ground for some trace of their beloved daughter, she soon realises she may be fighting for an unknown grandchild as well...