The plot focuses on bounty hunter Rick Deckard (likely a human), who uses a test of empathy (and a laser pistol) to filter his quarry from the humans left on Earth after a mass exodus to Mars. The humans left behind are mostly too damaged to merit inclusion in the exodus, and have been left on a radioactive-fallout-covered Earth to live as best they can. This includes the reportedly-mentally-deficient J. R. Isidore, who despite his categorization swings wildly between high and low levels of diction when narrating.
The usual Dickian mistrust of the world is pervasive; as Roger Zelazny writes in the introduction, "The worlds through which Philip K. Dick's characters move are subject to cancellation or revision without notice." Legally "deficient" Isidore pines, "If I hadn't failed that IQ test I wouldn't be reduced to this ignominious task with its attendant emotional by-products." (p.60) which offers a pretty good example of the sort of reader double-take that this book induces throughout. For several chapters around the middle of the book there are authorial hints dropped everywhere, the reader can't help but trip on them, suggesting that Deckard himself is an android, but later most of these hints are revoked. He finds a fellow bounty hunter who it seems certain is an android, but turns out to be human; he fails to empathize with some things, but later empathizes with others, so it's all okay.
A main focus of the book, and of the characters inhabiting the book's supremely editable world, is whether androids --- fully biological in construction --- can empathize, and how much, and what sorts of empathy are required to validate someone as a full person. Personhood is a focus, as it gives protection against the imminent threat of bounty hunting, but also it gives a larger protection in the book's strange and mostly-unexplained alien (?) religion of Mercerism, by which humans (and only humans, not androids!) can empathically fuse with all other religious participants, thereby escaping the bleak radioactive present reality. (Nevermind that they escape to a different bleak reality.) The takeaway message seems to be thus:
- Empathy makes personhood. (Anything passing the Turing test should receive the rights of a full human.)
- Opera does not protect against murder.
- Owls and spiders are valuable and underappreciated.
This post's theme word is ailuromancy, a form of magic especially focused on/with cats. (Brought to you by Mieville's Kraken, p. 400.) The electric veterinarians were not experts in ailuromancy, and so relied on their insurance policy to cover the dead (real) cat.