
In 2019, humans have genetically engineered Replicants, which are essientially humans who are designed for labor and entertainment purposes. They are illegal on earth, and if they make it to our planet they are to be hunted down and killed.
Rick Deckard is a blade runner, or a hunter of replicants. A group of replicants make it to Los Angeles to seek out a way to extend their life span. Replicants have a built in 4 year life span, and this group is at the end. Although he hunts them to the end, the replicants end up teaching the detached Deckard what it really means to be human.