One of the many memorable scenes in Ridley Scott's dystopian classic Blade Runner sees Rick Deckard (a spectacularly moody Harrison Ford) ring the house of a murder victim, introducing himself as a friend of the deceased as cover. His adversary, Pris (Daryl Hannah in her breakthrough role), takes the call, before abruptly bringing their VidPhone conversation to an end. "That's no way to treat a friend," Ford murmurs.
And Blade Runner fans - of whom there are many - could be forgiven for recalling those portentous words this week. Almost 30 years after Scott first introduced us to 2019 Los Angeles, starved of sunlight and populated by illegal androids (called replicants), a sequel has been confirmed. The original has become a cult favourite - an old friend that cineastes return to over and over again. And, judging by the concerned reaction on film sites around the world, those people are appalled that the power of this masterly science-fiction film might be lessened by this sequel.
Their reaction is ironic because almost nobody stood up for Blade Runner on its release in 1982 - not even Scott himself, who was furious with the studio for inserting narration and a happy ending to make the film easier to follow. But, over the years, the tale of Deckard's gloomy hunt for the replicants has gained critical and cultural momentum, despite its initial cool reception.
The 10th-anniversary Director's Cut and the 25th-anniversary Final Cut restored Scott's early vision. But even in its original guise, Blade Runner was a groundbreaking film, a combination of science and detective fiction set in a claustrophobic urban landscape cluttered by skyscrapers, neon advertisements and flying cars. No surprise, then, that in 1993, Blade Runner was preserved forever in the United States National Film Registry - an honour given to select films that are deemed "culturally, historically, or aesthetically significant".
So anyone who wants to take on this legacy clearly has to tread carefully. But there is a glimmer of hope for those who feared that "Blade Runner 2" - the project has no official title yet, nor even a screenplay - was likely to be as disappointing as another 1982 techno-themed cult classic recently given the sequel treatment: Tron Legacy. Not only has the film company with the rights to Blade Runner promised it won't resort to a straight remake, it has persuaded Scott himself to direct the new film.
"We are elated Ridley Scott will shepherd this iconic story into a new, exciting direction ... it gives people a level of comfort about how serious we are," the producers Broderick Johnson and Andrew Kosove told Reuters.
It'll certainly be fascinating to see what that "new, exciting direction" turns out to be, not least because this time there's no source text to adapt. Do Androids Dream of Electric Sheep?, Philip K Dick's 1968 novel on which much of Blade Runner is based, is a stand-alone book. Indeed, it's a measure of how influential the film version has been that, since 1982, Dick's bibliography has become de rigueur for excitable film studios keen to adapt his dystopian stories. Total Recall, Minority Report, A Scanner Darkly, Paycheck and this year's The Adjustment Bureau are all based on his work.
There is such a thing as being too influential, however. The look of Blade Runner - the monolithic cities, the postindustrial decay, the combination of high tech and scuzzy humanity that would go on to be called "cyberpunk" - has become the classic visual template for science-fiction films. The Matrix, The Terminator, The Fifth Element and many more have cheerfully stolen ideas from Blade Runner.
Unfortunately for Scott, once he's found a good enough story to tell (and we presume he will pass on the awful "authorised" Blade Runner books written after Dick's death), he also has to make it look distinctive all over again. As Kosove said: "We want to make sure we don't look like we're borrowing from the movies that borrowed from it."
And with Scott on board, that could easily mean a sequel that has only a passing resemblance to the original. After all, while grappling with the return to his other sci-fi masterpiece, Alien, he ditched the idea of a straight prequel and instead embarked on Prometheus, which, he told MTV News recently, had "strands of Alien's DNA" but was essentially a new story.
Prometheus is set for release next year, with "Blade Runner 2" following the year after. By which point Ridley Scott will be 75, and if he pulls off another groundbreaking futuristic tale, he will have deserved his retirement. But even if he doesn't, nothing can diminish the majesty of the original Blade Runner. Nobody is forcing anyone to watch a sequel. Which is something the apoplectic message board community would do well to remember.
Do Androids Dream of Electric Sheep? by Philip K Dick is re-released by Gollancz tomorrow