The narrative of Blade Runner follows Rick Deckard as he hunts four fugitive Nexus-6 replicants: Roy Batty, Zhora, Leon, and Pris. Deckard successfully 'retires' Zhora after a chase through crowded city streets and is then saved from being killed by a vengeful Leon when Rachael intervenes, shooting Leon with Deckard's gun.
Meanwhile, Roy Batty and Pris manipulate the lonely genetic designer J.F. Sebastian to gain access to their creator, Dr. Eldon Tyrell. In the film's pivotal confrontation, Roy demands 'more life' from Tyrell, who explains it is impossible. In a moment of rage and despair at his creator's impotence, Roy kisses Tyrell and then crushes his skull, killing him. Sebastian is presumed killed shortly after.
The climax occurs at Sebastian's apartment in the Bradbury Building, where Deckard retires Pris. He is then hunted by a physically deteriorating but immensely powerful Roy. The chase leads to the rooftops, where Deckard is left dangling for his life. In a stunning reversal, Roy, whose pre-determined lifespan is ending, chooses to save Deckard. With his final breaths, he delivers his famous 'Tears in rain' monologue, demonstrating a profound understanding of life and mortality before he dies. A shaken Deckard returns to his apartment to flee with Rachael. He finds an origami unicorn left by Gaff, a sign that Gaff knows about his private dream and has spared Rachael's life. The ending remains ambiguous, as the unicorn strongly implies Deckard is a replicant with implanted memories, just like Rachael, and that their future is uncertain.