Deckard crashes through the top floor window and finds himself dangling off a window ledge, several stories above the ground. Roy Batty howls like a wolf and kicks through a window below Deckard, who sits on the ledge. He calls Deckard's attack on him irrational and unsportsmanlike. Deckard climbs up the building towards the roof while Roy Batty swivels back into the window.
Cut to a closeup on Deckard's hastily bandaged hand as it searches for a ledge to hold on to. His broken fingers grip the ledge, and his face is contorted in pain as he pulls himself up onto the roof of the building. As Deckard gains his footing, Roy Batty emerges from an opening in the roof floor and stands to face the Blade Runner. Deckard runs and leaps onto an adjacent rooftop. Meanwhile, Roy Batty stands on the edge of J.F. Sebastian's building, looking at Deckard in a triumphant low-angle shot with streams of light framing his nearly nude form.
Roy Batty stands back, clutching a white dove to his chest, and jumps - landing on the roof next to Deckard, who slips, then dangles from a short piece of iron scaffolding. Batty stares him down, stating, "Quite an experience to live in fear, isn't it? That's what it means to be a slave". He continues smiling as Deckard slips some more - and spits up at Batty, refusing to ask him for help. But just as Deckard is about to fall, Batty reaches down and grabs Deckard's hand, pulling him up to the rooftop.
Roy hangs his head, crouching in front of Deckard. He slowly says that he has seen things that people wouldn't believe, and in time, those moments will be lost - like tears in rain. Finally, he speaks his last words: "time to die". The white dove flies away towards the sky. Hold on the closeup of Batty, his face hidden in a veil of shadow, the rain soaking his blonde hair. Deckard watches Batty for several moments. He hears a voice and turns to see Gaff standing on the roof in front of his police car. Deckard is now "finished". Gaff shouts, "it's too bad she won't live - but then again, who does?"
Cut to Deckard, his face red and pulpy, as he comes back to his apartment building. He keeps his gun ready as he walks in through the front door, calling out Rachael's name. The camera holds on a human-shaped lump under the sheets on Deckard's bed as he emerges in the background of the shot. Cut to a closeup on his gun as Deckard pulls back the sheets from Rachael's sleeping face. He leans in close to make sure she is alive - she is. She wakes up and Deckard asks her if she loves him. She says she does. He asks her to trust him.
Cut to the hallway outside Deckard's apartment. He comes out the door, cautious, and signals to Rachael when he is sure it's safe. She is dressed in her coat, and her hair is loose and curly. Deckard hears Gaff's voice in his mind - "it's too bad she won't live, but then again, who does?" He notices something shiny on the floor and bends down to pick it up - it's a tiny origami unicorn. Deckard takes the little souvenir and gets into the elevator with Rachael.
When Batty stands above Deckard and states, "quite an experience to live in fear, isn't it? That's what it means to be a slave", he is demonstrating to the Blade Runner that the two men have more in common than he might have suspected - setting up the revelation that Deckard may be a Replicant himself. Deckard is a slave to Bryant in the same way that Roy Batty has been a slave to Tyrell and the other humans who used him. They both have been forced to do jobs that most human beings cannot stomach - slaves to this Corporate, Orwellian system.
One of the enduring questions surrounding Blade Runner is, "why does Roy Batty save Deckard's life?" In his DVD commentary, Ridley Scott says that it "was an endorsement in a way, that [Batty] is more human than human, in that he can demonstrate a very human quality at a time when the roles are reversed and Deckard may have been delighted to blow [Batty's] head off". For his part, Deckard refuses to ask Batty for help and even spits at him. Scott claims that that as a result of Deckard's defiance, Batty has a "flash of admiration for the courage - from one warrior to another".
Additionally, Scott says, as Batty dies, he wants to "pass on the information that what the makers are doing is wrong - either the answer is to not make [Replicants] at all, or deal with them as human beings" (Sammon 193). As Batty hangs his head and gives his final, poetic speech about what he has seen, he is ensuring that by saying these words to Deckard, he is passing along his memories. "The gift of life is given by the person who dies", Scott asserts - a rare demonstration of humanity in the world of this film, and it comes from a being that is not even a real human. In fact, Replicants save Deckard's life twice in the film - Rachael saves him from Leon Kowalski on the street. We don't see human beings showing Deckard that same compassion - with the possible exception of Gaff. Bryant sends Deckard back into the streets after the Nexus 6 mutiny even though he knows that Deckard does not want to be in the Blade Runner game anymore.
Edward James Olmos (who played Gaff) said that Gaff made the origami figures as a commentary on Deckard's state of mind. In Bryant's office at the beginning of the film, Gaff makes a tiny chicken. In Leon's Hotel Room, he makes a matchstick man with an erection (to show that Deckard "had a hard-on because of the way he went after [the] case" (Sammon 129). To Scott, the origami unicorn is Gaff's way of telling Deckard that he has been at his apartment and has let Rachael live. Additionally, because of the unicorn memory we see in Deckard's mind earlier in the film, the origami unicorn is Gaff's way communicating to Deckard that he's read his file and knows his true identity (Greenwald). This leads the audience to conclude that the unicorn memory is very likely constructed from a real human being's imagination - meaning that Deckard is indeed a Replicant.
The question of whether or not Deckard is a Replicant has "generated more discussion on the internet than the existence of God" (Bukatman 92). Paul M. Sammon concludes that in the original 1982 release of Blade Runner, there is a strong possibility that Deckard is a Replicant, but in The Final Cut, there is no question that he is, mostly because of Scott's insertion of Deckard's unicorn fantasy.
However, Scott Bukatman (among others) believes that "it's urgently important that Deckard's status remains an open question rather than a settled doctrine... the state of radical doubt is central to the film [which is] predicated upon the unreliability of vision" (Bukatman 9). By the end of the film, Deckard has learned to "regard the Replicants as more than mere commodities" even before he finds Gaff's origami unicorn (Bukatman 83). If Deckard is a replicant, it is ironic that he discovers his humanity alongside the realization that he is not biologically human. Deckard and Rachael leave together, neither of them know how long they are going to live, but as Gaff says, everyone dies - Replicant or not - we all have limited time on this earth. Either Deckard can choose to live in fear of his death - whether it comes in 4 years or 40 - or he can choose to live whatever is left of his life to the fullest.