Blade Runner 3: Replicant Night is a 1996 science fiction novel by K. W. Jeter that continues the story of Rick Deckard. It is the sequel to Blade Runner 2: The Edge of Human, which in turn was itself a sequel to Ridley Scott's 1982 film Blade Runner.
After the events of Blade Runner 2, Deckard and Sarah Tyrell (who Deckard believed to be the replicant Rachael) had left to travel to the distant Off-world colonies. Deckard has also taken a job as a consultant to a movie company, which is producing a film about his experiences as a Blade Runner - a direct analogue of the real-world movie Blade Runner. Deckard learns that the replicant character Leon is being played by an actual replicant, who is retired live on camera. Outraged, Deckard goes to find the movie director, a man named Urbenton and finds that he has been locked in a storage closet, and did not sanction the retirement.
Meanwhile, Deckard's former partner Dave Holden is sneaking into the movie studio to deliver a package to Deckard. Holden is caught and taken into a stage re-enactment of his own interview with Leon, in which Holden is shot with live ammo at the end of the scene. Deckard and the director rush to investigate and find that the scene has been arranged by a man named Marley, who kills the Leon replicant on the spot. Deckard tries to attack Marley, but Marley argues that Deckard has no evidence of any wrongdoing: all that Deckard has seen Marley do is to retire a replicant.
Deckard leaves the movie studio, but takes with him the item that Holden had been trying to deliver to him - a suitcase. The suitcase, it turns out, is intelligent and contains a working personality image of Roy Batty, taken from the human Roy Batty that Deckard originally fought in Blade Runner 2. Roy explains to Deckard that a group of replicant sympathisers require Deckard to perform a mission for them. Isidore (the version of the character present in Blade Runner 2) had previously run a business modifying replicants visiting Earth so that they would be able to pass a VK test. As part of the modification, the replicants were made to forget that they even were replicants, but each one was also programmed with a secret code that would re-enable their full knowledge. The briefcase contains an encrypted form of Isidore's list of secret codes. The rep-symps want Deckard to take the package out to the replicants on the distant off-world colonies, who can decrypt the information and securely send it to Earth for the rep-symps to use to recruit Earth's replicants for the insurrection.
Meanwhile, Sarah Tyrell is living on Mars. There are no ships traveling to the off-world colonies and there have not really been any for years. The level of available activity and stimulus on Mars is so low that it inevitably drives humans insane. Sarah also now knows that Deckard has realized she is not really Rachael (after she tried to masquerade as her in Blade Runner 2), and he does not love her. Sarah's only remaining ambition is to kill Deckard and then kill herself. She is visited by two agents of the Tyrell Corporation. Sarah is surprised, since she believed that she destroyed the Tyrell Corporation, but the agents explain that they work for the "shadow corporation", and they need Sarah to return with them to help discover an artifact from the Tyrell Corporation's past - the "Salander 3".
The Salander 3 was the last ship to travel from Earth to the far worlds. Two people travelled on it: Ruth and Anson Tyrell. Sarah is their daughter, born on board the Salander 3. What exactly happened on board the Salander 3 has never been known, other than that the ship did not complete its voyage and ended up returning to Earth and the only living person on it after it arrived was Sarah; Anson and Ruth were both dead. This is the reason why no ships ever leave for the far colonies any more. The Salander 3 has been buried in a secret dump site on Earth. Reluctantly, Sarah goes with the two men and descends into the wreckage of the Salander 3. There, she sees her own name written on a wall in blood and meets a young ten-year-old girl, identical to herself, who claims that her name is Rachael.
Sarah believes that the girl is a hallucination, an image of her own younger self. Exploring further, she finds whole areas of the ship are covered in blood and the remains of humans and animals and is nearly herself attacked by a stumbling, severely wounded image of her father. Sarah flees the Salander 3 and is rescued by the two Tyrell agents, but is shocked when they claim that they can also see the little girl; they rescue her too. Sarah remains convinced that they cannot really see Rachael and are pretending to be able to in order to drive her mad. Sarah, "Rachael" and the two agents talk about what they saw. It appears that Anson Tyrell went insane and attempted to murder Sarah, but murdered Ruth instead and then killed himself upon realising what he had done. However, there is still no clue as to why Anson Tyrell would go insane. The two Tyrell agents ask Sarah to return to the Salander 3 to find out more information and she agrees as long as she is given a gun to defend herself with; after receiving the gun, Sarah shoots both the agents and leaves with Rachael.
Meanwhile, inside the suitcase Deckard finds a packet of powder, marked "Sebastian". The replicant sympathisers have transformed Sebastian into a "dehydrated deity" - actually, his personality has been embedded in an array of microscopic sensory override capsules. By ingesting the capsules with proper preparation, Deckard can meet with Sebastian's personality, in an artificial world that Sebastian controls. Deckard takes the powder and appears in a clone of the Bradbury Building, where Sebastian had previously lived, and where he now lives again.
Sebastian has been able to rebuild the building and area he previously loved, and has restored the replicant-like toys he built, but he is upset that he has been unable to bring Pris back. Sebastian tells Deckard that the image of Batty inside the box is not lying, and that the U.N. will completely wipe out the replicants on the colonies unless the insurgency can stop them. Sebastian then admits that there is some information that the rep-symps did not want him to give Deckard, but that he will do so anyway because Deckard has given him hope: he says that the mission is far more important that Deckard realizes, as it is to do with humans as well, and the difference between humans and replicants. Sebastian gives Deckard a box, and then Deckard awakens from the artificial world. Examining the box, it appears to be an ordinary, ancient first-aid kit. Deckard thinks of throwing it away, but decides to keep it, since it was important enough that Sebastian gave it to him.
Deckard returns to the colony on Mars, where he meets up with Sarah and Rachael again. Sarah still insists that Rachael is a hallucination and when Deckard is able to converse with the girl, Sarah insists that Deckard is in league with the Tyrell agents and is conspiring to drive her insane. When Deckard hears that the girl's name is Rachael, he asks her directly about Ruth Tyrell and the Salander 3 and she answers positively. Sarah is about to shoot Deckard, but Deckard manages to trick her and escape, taking Rachael with him. After Deckard leaves, Sarah becomes enraged; and at that moment, Urbenton - the movie director - visits the apartment, explaining that he has an interest in arranging Deckard's death, which he has learned that she shares.
Deckard goes with Rachael to a bar on the colony, where he is ambushed by Marley. Marley shows no desire to fight with Deckard, instead asking him to watch the TV. The "Blade Runner" film appears on TV and Deckard realises he has been trapped. When his image is shown on the film, everyone on Earth and the colonies will know who he is, and any attempt at passing undercover with the suitcase will be impossible. However, when the film actually starts, the face imaged onto the actor is not Deckard's (as he was told it would be), nor does it even resemble him. Deckard is amazed and Marley explains that this has happened because the film has been edited by the cable company at the government's orders. The UN wants Deckard to get through with the briefcase; it has not been sent by the rep-symps at all. The truth that the government is afraid of is that, out on the far colonies, replicants are able to live more than four years. Not only that, but they are able to breed - and, they show clear empathy. Humans, on the other hand, age and deteriorate more quickly, and universally become sterile. In other words, on the far colonies, humans become replicants, and replicants become humans.
When Eldon Tyrell designed the original replicants, he included a failsafe mechanism to prevent replicants from breeding: male replicants suffer from an amplified, modified version of "stepfather syndrome", the animal instinct to kill the children of other males. Male replicants, however, have an instinct to kill their own children. In most replicants, this instinct is suppressed unless activated; the information in the briefcase is the trigger signal that will activate this, wiping out the replicant families forming on the far colonies. Finally, Marley takes out the first-aid kit that Sebastian gave Deckard, and reveals that a photograph is hidden in one of the compartments; but before Deckard can see the photograph, UN troopers burst in with guns. Deckard moves to shoot at them, but his gun is snatched by Marley, who uses it to shoot at and destroy the briefcase before Marley himself is shot dead by the troopers. The troopers seize Rachael, and take her away, leaving behind a business card for the film company.
In pursuit of Rachael, Deckard returns to the film studio, where the director has set up a series of scenes intended to climax with Sarah killing Deckard live on camera. Deckard finds the Rachael child in a replica of the Bradbury building; he encounters Sarah on the roof. Sarah explains that this will be the final scene of a new version of the film, a version that will be shown on Earth as a documentary; a version where Deckard dies at the end of the film, increasing the anti-replicant sentiment on Earth to fever pitch. Deckard challenges Sarah, showing her the photo from the first-aid kit. It shows Anson and Ruth Tyrell, in uniforms from the Salander 3 - cradling two infants.
Rachael is Sarah's twin sister. Sarah protests that if they were sisters, they would be the same age now. But Deckard replies that they are not, because Rachael was held in a sleep capsule, hidden there by Ruth to save her from Anson's rampage. The purpose of the Salander 3 mission was not to visit the far colonies at all. The purpose of the Salander 3 was to fly towards the far colonies and then return, to see what effects occurred in their vicinity. Anson and Ruth Tyrell were replicants, specially engineered to be unaware of that fact; and when the ship got far enough away from Earth, they became able to breed, and gave birth to Rachael and Sarah. But then, as a male experimental replicant, the modified stepfather syndrome programmed into Anson activated: he was able to murder Ruth before his new-found empathy overrode his programming and he killed himself, and the two children returned to Earth. Rachael was hidden in a sleep capsule, but Sarah remained exposed. When the ship returned to Earth, Sarah stepped off it. She is the first replicant child.
Even Eldon Tyrell could not simply order the destruction of a child, especially given that she was unaware that she was a replicant, so he did the best he could to cover up the entire incident. Sarah is deeply shocked, and finally admits that she could only deny that Rachael truly existed because she had known, even since she first saw her, that Rachael was truly her sister. Sarah finally knows what she had always wanted to know. Distraught, she asks Deckard to kiss her, the way he kissed Rachael, and finally commits suicide in Deckard's arms. Deckard and the child Rachael leave the movie studio, unsure of where they are going.