Do Androids Dream of Electric Sheep? is a science fiction novel by Philip K. Dick first published in 1968. The main plot follows Rick Deckard, a bounty hunter of androids, while the secondary plot follows John Isidore, a man of sub-normal intelligence who befriends some of the androids. The novel is set in a post-apocalyptic near future, where the Earth and its populations have been damaged greatly by Nuclear War during World War Terminus. Most types of animals are endangered or extinct due to extreme radiation poisoning from the war. To own an animal is a sign of status, but what is emphasized more is the empathic emotions humans experience towards an animal. Deckard, the protagonist, is faced with retiring six escaped Nexus-6 model androids, the latest and most advanced model. Because of this task, the novel explores the issue of what it is to be human. Unlike humans, the androids possess no empathic sense. By introducing organic and realistically humanoid androids in this novel, Dick asks what qualities, if any, are unique to or are able to define what is human and makes readers question their own humanity. The book's plot served as the primary basis for the 1982 film Blade Runner.