Beginning several months after the events in Blade Runner, Deckard has retired to an isolated shack outside the city, taking the replicant Rachael with him in a Tyrell transport container, which slows down the replicant aging process. He is approached by a woman who explains she is Sarah Tyrell, niece of Eldon Tyrell, heiress to the entire Tyrell Corporation and the human template (templant) for the Rachael replicant. She asks Deckard to hunt down the "missing" sixth replicant. At the same time, the human template for Roy Batty hires Dave Holden, the blade runner attacked by Leon, to help him hunt down the man he believes is the sixth replicant - Deckard.

Living on Mars, Deckard is acting as a consultant to a movie crew filming the story of his Blade Runner days. He finds himself drawn into a mission on behalf of the replicants he was once assigned to kill. Meanwhile, the mystery surrounding the beginnings of the Tyrell Corporation is being dragged out into the light.

The story begins with the introduction of Iris, a female Blade Runner, and the best in her unit. Meyer - her boss - tells her that the blade runner division is in danger; far fewer replicants are coming to Earth, and thus the economic value of the blade runners is dropping, giving the risk of a "reorganisation". Meyer gives Iris the assignment to track down an owl - an extremely rare, real owl, named Scrappy. Iris is skeptical, since if the owl is real (and thus not a replicant) the case seems to be nothing to do with the blade runners, but she accepts the job anyway.