2019 marked the death of Eldon Tyrell, the genius behind the Tyrell Corporation, and Rick Deckard's hunt for fugitive Nexus-6 replicants led by Roy Batty and his flight from Los Angeles with prototype Nexus-7 Rachael.
The city of Los Angeles of 2019 is depicted as a technologically advanced society. Automobiles called Spinners are able to fly above the streets which are clogged with people and ground-based automobiles. The streets of the city are lined with shops, cafes and clubs. Dominating the skyline are the twin pyramids of the Tyrell Corporation, skyscrapers and smokestacks of countless factories and industrial factories. Additionally, large blimp-like vehicles called Sub-Neural ads float above the streets promoting life in the "off-world" colonies for new living space now that travel to worlds other than Earth is possible. These Blimps also promote other products for people to buy. The sky appears consistently overcast and smoggy. Rainy weather is a common meteorological occurrence in the city. The rain contains pollutants from the many factories falling back on the ground called "acid rain".
By 2019, the Tyrell Corporation has introduced the science of "replication;" the engineering of human-like androids. Most replicants are manufactured for manual labor purposes in the off-world colonies. However, Replicants have proven to be dangerous to humans and have been declared illegal on Planet Earth. At the core of the film's story is the attempt by a small group of replicants to return to Earth to extend their genetically engineered four year life span. Their attempts to do so prove futile because it is impossible to alter a genetic sequence post-replication.