Do Androids Dream of Electric Sheep? is a book that most people think they remember, and almost always get more or less wrong. Ridley Scott's film Blade Runner took a lot from it, and threw a lot away; wonderful in itself, it is a flash thriller where Dick's novel is a sober meditation. As we all know, bounty hunter Rick Deckard is stalking a group of androids returned from space with short life spans and murder on their minds--where Scott's Deckard was Harrison Ford, Dick's is a financially over-stretched municipal employee with bills to pay and a depressed wife. In a world where most animals have died, and pet-keeping is a social duty, he can only afford a robot imitation, unless he gets a big financial break. The genetically warped "chickenhead" John Isidore has visions of a tomb-world where entropy has finally won. And everyone plugs in to the spiritual agony of Mercer, whose sufferings for the sins of humanity are broadcast several times a day. Prefiguring the religious obsessions of Dick's last novels, this asks dark questions about identity and altruism. After all, is it right to kill the killers just because Mercer says so? --Roz Kaveney