Early in the 21st Century, the Tyrell Corporation advanced robot evolution to the Nexus phase – creating artificial beings virtually identical to humans – known as Replicants.
Superior in strength and agility, the Replicants functioned primarily as Off-world slave labor or in hazardous, high-collateral combat situations.
After replicants were declared illegal on Earth, special police operatives – called Blade Runners – had orders to kill or 'Retire' any trespassers upon detection.
Detective Aahna Ashina of the Los Angeles Police Department was one of the first to qualify for the assignment.