Blade Runner 2049 is not your everyday sequel. The film continues the story of Blade Runner, a bona fide sci-fi classic that was released way back in 1982 at a time when sequel star Ryan Gosling was only 17 months old. So clearly, there are going to be a lot of changes with the new film's cast compared to the original. However, there are some returning faces, including Harrison Ford as Rick Deckard and Edward James Olmos as Gaff, but the most puzzling is the appearance of spoiler alert! young Rachael in Blade Runner 2049.
In the first film, Rachael was a replicant portrayed by Sean Young. She was no ordinary replicant, though, she believed herself to be human thanks to false implanted memories. Whereas other replicants knew what they were, Rachael didn't, at least not until later on in the film. She eventually becomes romantically involved with Deckard, the blade runner who is assigned to retire her. At the conclusion of Blade Runner, Deckard and Rachael end up together and presumably go on the run, as by the time 2049 begins, Deckard has been missing for 30 years. Rachael, meanwhile, should be long dead, since replicants like her have a very finite lifespan. Yet that doesn't stop her from appearing in the film.
In the sequel, a hologram of Rachael appears looking pretty much exactly as she did in the original film 35 years ago. In the world of the film, Rachael is long dead, and the vision of her is constructed by replicant creator Niander Wallace (Jared Leto) in an attempt to mess with Deckard (this effort ultimately fails). But since actor Sean Young is now 57 years old and doesn't look much like she did in 1982, the movie must have used some other method to bring the character back. So how did they do it?
The producers of the film have not yet revealed how they went about bringing back Rachael for Blade Runner 2049. The most likely scenario is that the character was made using CGI. There was a rumor, first seen earlier this year on The Terminator Fans and subsequently picked up by a number of other publications, that a replicant from the original Blade Runner — possibly Rachael — would be created using CGI. Fans have seen this technique used in a number of recent films, most notably in Rogue One, which featured computer-generated recreations of young Princess Leia and Grand Moff Tarkin. In both of those instances, the original actors had no role in producing the digital versions of themselves — Peter Cushing, who originally played Tarkin, passed away in 1994.
However, Cushing's estate and Carrie Fisher both gave their permission for their likenesses to be used in the film. Therefore, fans can assume that Rachael's appearance in Blade Runner 2049 required at least the permission of Sean Young, if not her direct involvement. This is where things get a bit tricky.
Young has given no indication that she was involved in the new film, and at times has seemed somewhat hostile toward the idea. In 2013, she told EW that if the film didn't include her, "everybody should boycott it." In a 2015 Guardian interview, however, she seemed less opposed to the idea of a sequel, but seemed pretty sure she wouldn't be in it. "I saw Ridley a month ago and not a peep was uttered from his mouth about it and so I left it alone," Young said at the time.
However, it's possible that this status could have changed. The New York Daily News claimed in September of this year that Young had secretly filmed scenes for the new movie. "Sean Young will feature in the new film," the paper quoted a source close to the production. "She filmed the scenes in secret with minimal crew knowing about it, and even the editors have been on lockdown about her appearance." It's also worth noting that, in his review of the film, Variety's Peter Debruge lists Young as a member of the cast.
It seems a given that Blade Runner 2049 remade Rachael from Blade Runner using CGI technology, but without confirmation that Young aided them in doing so, it's impossible to say at this time just how they went about doing it, making it quite possibly the neo-noir's biggest mystery.