The original Blade Runner was set in the future of 2019. Today, 35 years after that now-classic movie appeared, its world hardly seems strange at all. Androids have popped up on screen everywhere, from Steven Spielberg’s underrated AI: Artificial Intelligence to Westworld. Video phones are common. The constant rain in the film seems like a forecast of the climate change that has deluged the globe with tragically strong hurricanes. How can a futuristic film outrun 2017’s reality?

Denis Villeneuve’s shrewdly calculated sequel, Blade Runner 2049, tries hard to evade that tricky problem, with a busy, distracting surface that cloaks an enduring theme about humanity.

The action is set in a sci-fi dystopia. Instead of focusing on the technology that led to that mess – a backstory seeps in, involving famine and a catastrophic data-destroying blackout – the film takes an issue planted in the original movie and makes it the sequel’s central, resonant mystery. Do memories make us human? If not, what does?

There is a more overt mystery, of course. The sequel wisely borrows the original’s detective-in-dystopia premise, and even more wisely cast Ryan Gosling as Detective K. The all-but-human androids known as replicants, outlawed in the first film, have been replaced with spiffy new legal models. Like Harrison Ford’s Richard Deckard in the original, K is a Blade Runner charged with tracking down and eliminating out-of-date replicants.

At two hours and 43 minutes, Blade Runner 2049 plays as if it were three installments of a franchise. Much of it is cautiously efficient, too protective of its legacy to invent something audaciously new. The first section builds the film’s fictional world. K leaves a more decrepit version of the old Blade Runner’s Los Angeles, tracking down a possible replicant. He finds Sapper Morton (Dave Bautista), a worm farmer -- worms are food in 2049 – and the film kicks off with a volatile fight scene. Someone goes flying through a wall.  

That action seems like an obligatory way to grab viewers, but the world-building is more concerned with K at home. Waiting in his apartment is his girlfriend, Joi (Ana de Armas). She is part Siri, part Alexa, part Scarlett Johansson’s Samantha from Her. It would be good to know why one of her idealised iterations is a 1950s style housewife in heels and pearls, but we never find out. Those scenes effectively reveal K’s loneliness. They also play like echoes of Her rather than a knowing nod. Among the intentional nods: an unexpected allusion to Pinocchio.

The plot takes off during the film’s second hour. K finds something buried under a tree at the worm farm. (Nothing in this earnest film encourages viewers to laugh at the idea of the worm farm, but go ahead.) The discovery sends K, on orders from his boss –Robin Wright, in stern commandant mode – on a quest to find the meaning of the object he has found.

Along the way, he begins to question his own past and identity, roving through unsettling, half-grasped memories of childhood. Gosling is a master of understated acting, able to display a thought with a simple glance. His low-key intensity fits perfectly in a world with a shortage of human emotions on display. It says a lot about Gosling’s strengths that from the start he evokes warmth and sympathy in a pretty chilly film.

Villeneuve juggles action and theme with precision, and gracefully drops in information. Anyone unfamiliar with the original Blade Runner won’t be lost. Each scene is packed with so many small touches that the movie comes ready-made for fans to debate and analyse. K’s girlfriend call him Joe; Kafka’s Joseph K must be so proud. K’s flying car, an updated version of the original’s spinner, now comes with a detachable drone on the roof. 

But the sequel can’t escape the fact that the strength and lasting influence of Ridley Scott’s original Blade Runner was its look: the midnight-blue light that played like a scrim over a rainy, neon-bright Los Angeles resembling Tokyo; the golden-yellow interiors that created a haunting aura for a jaundiced world.

The sequel borrows the golden-yellow palette for some scenes. Overall, cinematographer Roger Deakins and production designer Dennis Gassner create a grim, ashy-grey world. Villeneuve shot a great deal on sets and locations in Hungary. The film may not be heavy with CGI, but it looks as though it is. That’s not a bad way to depict a blighted future, but the design is never as engaging as the gloriously rich original.

The film makes very few actual missteps, but they exist. Jared Leto, wearing milky contacts as a blind genius and corporate tycoon who solved the food crisis, is pallid on screen, a stylised cliché.  The music, by Benjamin Wallfisch and Hans Zimmer, can be intrusive, and is especially cloying at a moment when K makes an important discovery.

But there are many strong scenes that reveal the freshness the film could have used more of. K’s quest takes him to a dark, old-fashioned warehouse where orphaned children work on computer circuitry, a combination of Dickens and your worst fears about how your phone was made. He visits a soft-spoken young woman, isolated in a large plastic tent because of an immune deficiency. Her job is to manufacture memories to be implanted in replicants, and the emotional connection between her and K is lovely.   

But through the first two hours there is a nagging sense of something missing. Finally, K’s search leads him to Richard Deckard, the original Blade Runner, and Harrison Ford jolts the final 45 minutes or so, making the last stretch exceptional.

The first film ended with Deckard on the run with his replicant girlfriend, Rachel. At least that’s the end in the Final Cut version, Scott’s preferred among several incarnations. All versions set off decades of speculation about whether Deckard himself was a replicant.

But Ford doesn’t enliven the film for nostalgic reasons. He brings fierce, potent energy to the role, capturing Deckard’s suspicion of K, protectiveness about his past, and will to survive.  In a career of iconic roles, this is among his best.

Ford also energizes Gosling’s performance. First tangling verbally, then with their fists, and eventually swerving into the film’s huge revelations, they call on every bit of their movie-star charisma, not in a tacky Oscar-baiting way but as actors who know how to hold a screen. It helps that Deckard lives in the film’s one witty location, an old casino where holograms of Elvis and Sinatra intermittently appear on the abandoned stage. The film’s most ingenious stroke also involves Ford. It’s possible to leave Blade Runner 2049 assuming you know whether Deckard is a replicant, only to look back and second-guess yourself.