Innocent Blood (1980) is a mystery novel by P. D. James.
A young woman, Philippa Palfrey, finds out that her father and mother are actually her adoptive parents. Her adoptive father, Maurice, is a lecturer at a school. He is also a spokesperson for the Young Socialists party and a writer of textbooks on sociology. Philippa's adoptive mother, Hilda, is a magistrate with a local Juvenile court and an amateur cook. At the age of 8 years old, Philippa suppresses memories of her biological parents and in the intervening years, creates an idealised version of her parents. Upon learning of her biological parents, Philippa conducts a rudimentary investigation of her biological parents and discovers the truth of the crime: her biological parents were convicted ten years ago for the rape and murder of a young girl, Julie Scase, which caused her to be put up for foster care and eventual adoption by the Palfreys. She discovers her father died in prison a few years after the conviction and her birth mother is still alive, due to be released after 10 years in an English women's prison. She returns home after the discovery and confronts Hilda, who is shocked and dismayed to learn the adoption order was unsealed. It is after a strained dinner party with three guests where Philippa places her adoptive family in a position where the elder Palfreys have a contentious argument with Philippa. When her mother, Mary Ducton, is released from prison, Philippa looks her up, decides to live with her in a small flat in London and try to recreate the mother-daughter relationship. They rent a small flat in Central London and have a menial job at a fish and chips shop to supplement Philippa's meager savings.
Mary Ducton provides Philippa with an account of the murder/rape and a bit of background information on the rapist, Martin. It is revealed later that the account was written recently, presumably for Phillipa's benefit.
Norman Scase, the father of the murder victim, has sworn vengeance and prepares to track down Mary and kill her as Julie's mother and Scase's wife lie dying in a hospital. Through deception, his own methods of surveilling the Palfrey residence, a clever call to the Palfrey residence, and the use of a shady private investigator, Norman Scase discovers the murderess and Philippa. At the same time Norman Scase is conducting his own search, a school friend of Philippa's has other intentions: he intends to blackmail Philippa and Mary Ducton for his own reasons. He too manages to trick Hilda into revealing the location of the rented flat and tips off one of his paramours, a young reporter.
The novel reaches its climactic ending when Scase breaks into the flat after Mary Ducton commits suicide and Scase stabs her. Philippa orders him out and she takes the blame for the murder, but it is Maurice who has the strings pulled so she is not connected to the stabbing. The last chapter ends with Philippa meeting Norman Scase in a church and the revelation she has published a book under her new name, Philippa Ducton.
"P. D. James chose to write a novel in which crime might figure but would not be the mainspring of the action. The work is a great success -- with the public and with the connoisseurs. ... The diverse characters are admirably drawn and the author's fingerwork in tying and untying threads is as deft as her touches of sordid life and as nimble as her prose."[1]