Innocent Blood by P. D. James (Paperback)

Adopted as a child into a privileged family, Philippa Palfrey fantasizes that she is the daughter of an aristocrat and a parlour maid. The terrifying truth about her parents and a long-ago murder is only the first in a series of shocking betrayals. Philippa quickly learns that those who delve into the secrets of the past must be on guard when long-buried horrors begin to stir.