Based on official plot summary - a possible idea what the story is about
Thirty years after the events of the first film, a new blade runner, LAPD Officer K (Ryan Gosling), unearths a long-buried secret that has the potential to plunge what's left of society into chaos. K's discovery leads him on a quest to find Rick Deckard (Harrison Ford), a former LAPD blade runner who has been missing for 30 years.
I've no idea if the following is what we may see in BR 2049 - probably not - but here is one possible idea what the story could be about...
What if humanity is dying? Perhaps a disease is making the population infertile or a new virus threatens mankind. The government decide the only way to preserve the human race is create replicants. These machines will replace humans.
Deckard was an early prototype 'humanity replacing' replicant. This explains why he ages. He never knew he was a replicant, of course. But the bigger twist in Blade Runner 2049 is...
Every person born after the ending of the original Blade Runner film is a replicant. Ryan Gosling's K is a replicant, all the people of the last 30 years are replicants and they don't know. That's the secret. Humanity is dying out and the governments of the world (or in this case, the US government in Los Angeles) - funded by some evil corporation - has replaced humans with replicants. Replicants that can age, that have full memories of their early years etc. These replicants also have sexual desire, fall in love, and the birth of their children is also artificial. Replicant children born in replicant womens' wombs.
The statue in the teaser represents the fall of humanity, the end of humanity. The broken face of humankind.
K discovers the huge secret and assists Deckard in a mission to stop the replicant program.
I'm not a huge fan of Deckard as a replicant - I don't think he is a replicant in the original Blade Runner. I thought Blade Runner was about a human falling in love/caring for a replicant (Rachel). Can a human fall for a machine/can a machine fall in love with a human? That appeared to be one of the main themes of the original film. But if Deckard is going to be a replicant in BR 2 it might make plot sense to have him as a prototype replicant - one given the gift or curse of aging, of a long life. And the success of Deckard convinced the government to go ahead with mass production of aging, long life replicants. These replicants were implanted with human DNA and through replicant sex it was possible to create new replicants thereby ensuring the human race continues but not the real human race, a fake replicant version!
I believe this could work as a plot and be a cool twist. Replicants replacing every human but no-one knows. Humankind replaced by replicants. The ultimate deception.
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