P. D. James is a mystery writer who with [Innocent Blood] has abandoned mystery. She began as a writer of orthodox detective stories in the English tradition. Her first book, Cover Her Face, opened with a tea party, and offered fairly conventional characters in a rural setting. But this book and its immediate successors seem not to have satisfied her, and in Shroud For a Nightingale (1971) she used her professional knowledge as a hospital administrator to give a realistic portrait of the Nightingale Training College for Nurses. The Black Tower (1975) is set in a home for incurables, and the crime is investigated by a detective who has just been reprieved from what was in effect a death sentence, a diagnosis of leukemia.

The detective, Commander Adam Dalgleish, appears in her first seven books, but the portrait of him is deepened and strengthened in The Black Tower and in...