Canadian director Denis Villeneuve fended off numerous requests to direct big-budget sequels but then he was asked to do the follow-up to Ridley Scott's 1982 neo-noir sci-fi film Blade Runner.
"I accepted to do Blade Runner because it was meaningful," says Villeneuve, director of alien sci-fi film Arrival (2016).
"The resonance of the first movie in my life, the love I have for it, it's worth it to take that risk."
Blade Runner 2049, due for release on October 6, is set 30 years after the events of the original film, when human-like robots - Replicants - were hunted by police in a dystopian Los Angeles.
"We created a world that is an extension of the first movie, a projection of its future, where some laws and some rules will be in relationship with the first movie and not with today," said Villeneuve.
The first film followed Harrison Ford as "blade runner" Rick Deckard, an expert on hunting humanoid Replicant robots living illegally on Earth, against a backdrop of a futuristic LA depicted as a hybrid of eastern and western cultural influences.
In a trailer released this week, the sequel returns to a dystopian California after the ecosystem has broken down, and an LA police officer (Ryan Gosling), Agent K, stumbles upon a secret that could jeopardise society. He seeks out Deckard, who has been missing for 30 years.
Villeneuve, Ford and Gosling were joined by other cast members on Saturday at San Diego's annual Comic-Con to discuss the sequel and debut new footage. This shows a world where Replicants and humans live alongside each other, but not in harmony.
"The original film explored the ethics of the creation of the Replicants and their utility and we further developed those themes in this story," said Ford.
Villeneuve told Reuters he had worked with Ford to evolve Deckard's character. "There's a melancholia that I like in the first movie that we kept alive in Deckard, and something taciturn, not someone who talks a lot, and a sadness to the character that is there and existential doubt," he said.
The sequel will stay close to the original's themes of identity and memory, Villeneuve added.
"I don't think the movie will necessarily say interesting things about our future, apart from the fact we're still there, but it'll say things about today, for sure."