Queen of Angels is a novel written by Greg Bear. It was followed by a sequel, "/", also known as Slant.
Queen of Angels describes our world just prior to the binary millennium (2048 AD) through several parallel (and to some degree interlocking) tales. Nanotechnology has transformed almost every aspect of American society, and its application to psychology, psychiatry, and neuroscience has resulted in new techniques for mental "therapy" that have created new forms of social stratification. Increasingly, individuals are "therapied" - that is, well-integrated personalities capable of productive work and constructive social interaction which does not threaten the social order. Therapied individuals have access to the best jobs. There are two other classes: the "high naturals", who possess such a positive mental makeup without the need for therapy, and the "untherapied", who find themselves increasingly marginalized.
The central unifying element involves a famous writer, Emmanuel Goldsmith, who has committed a gruesome series of murders, a crime almost unheard of in the age of therapy. One storyline involves Mary Choy, a high natural police detective assigned to the case to track down and arrest the murderer. Mary is a transform - her body has been extensively altered by nanotechnology to enhance her abilities as a policewoman.
A second storyline involves Richard Fettle, a good friend of the murderer, also an untherapied writer, who must come to terms with what happened to his friend and how his life--and that of artists, and all of the untherapied--must change. The third plot line concerns Martin Burke, a pioneer in psychotherapy who uses a technique which allows him to directly enter and interact with a patient's psychology - the "Country of the Mind" - through a sort of virtual reality. Although in a position of disgrace at the story's opening, Dr. Burke is given the opportunity to use his technique to explore Goldsmith's mind, which turns out to be one of the most fascinating and dangerous minds imaginable.
Finally, the fourth plotline considers the nature of artificial intelligence, as an AI robot space probe discovers life on a planet in the Alpha Centauri system, and simultaneously achieves its own independent self-awareness, as does its twin back on Earth.
The novel deals with issues of technology, identity, the nature of justice, and the existence of consciousness and the soul.