Based on a true story, 'The Walk' follows the ambition of a Frenchman planning to walk a tightrope between the Trade Centre buildings in New York.
Director Robert Zemeckis made Forrest Gump run and sent Marty McFly back to the future. Why does he hope his new film will make you sick? Robbie Collin reports.
Imagine standing on the edge of a very tall building. There's no handrail, and as you crane forward and look over your toes, all you see beneath you is a clean, 300ft drop to the pavement.
What's making you nauseous isn't the thought of the fall, but the empty space itself, which contains none of the short-to-mid-range visual cues that your brain normally uses to gauge how well you're balanced. And that makes your brain worry that you're not actually balanced at all.
And as it tries to get the measure of the situation, adjusting your posture to see what's gone wrong, you start swaying forwards into that empty space, until your lack of balance is no longer an optical illusion.
The medical term for this is "visual height intolerance", though it is often wrongly called vertigo, which is a completely different balance-related complaint. But for Robert Zemeckis, the Oscar-winning director of Back to the Future, Cast Away and Forrest Gump, the sweating and swaying means something else entirely. Fun.
The Walk, Zemeckis's latest film, turns visual height intolerance into an art form. It's a 3D dramatisation of one of the most famous high-wire stunts in history: Philippe Petit's 1974 crossing between the North and South Towers of the World Trade Center in New York City, which he completed without a safety harness, a net, or permission.
The film begins in Paris six years before the stunt, with Petit, played by Joseph Gordon-Levitt, making preparations for what he calls "the artistic crime of the century". But gripping and snappy as this stuff is, it's all in service of the walk itself, which begins with Gordon-Levitt standing on the South Tower's observation deck, 400m above the ground, and stepping into thin air.
The Walk features on the cover of this week's TimeOut:
I meet the 63-year-old director in a suite on the seventh floor of a hotel in Barcelona, which feels high enough under the circumstances. I'd seen The Walk the previous night, and tell Zemeckis that halfway through Petit's stunt, my notepad started sliding off my lap. I didn't notice until it finally fell on the floor, when I almost had a heart attack. I honestly thought it was dropping 110 storeys to the ground.
"Good, good," he says, smiling and furrowing his brow, like a scientist watching a predictable guinea pig. "That wasn't an accident."
The film uses 3D to create, not an illusion of depth, exactly, but a very specific impression of height. "Because you can be in an aeroplane at 35,000 feet and look out of the window and not get creeped out," he says, "but you can be on a 10ft ladder and look down at your feet on a rung, and think 'I could fall and break my neck'."
To capture this on screen, Zemeckis and his visual artists had to do two things. The first was to create a meaningful visual relationship between the audience, Petit and the ground. And the second was to use the camera and perspective to induce what Zemeckis calls "subconscious movement": the sense of high-up-ness, the imaginary wobble.
The visual, technological and psychological mechanisms behind this are bewilderingly complex, but you can sum up their effect in three words. You're up there.
Joseph Gordon-Levitt stars as Philippe Petite in The Walk.
It's not hard to work out why Petit's stunt appealed to Zemeckis. This is, after all, the film-maker who brought cartoon characters crashing into film noir in Who Framed Roger Rabbit, and sent a real man ambling through historical newsreels in Forrest Gump.
Zemeckis is one of the younger members of the movie brat generation -- the film-school trained directors who flooded into Hollywood's studio system in the 70s and early 80s, with big things to prove.
His contemporaries are Steven Spielberg, George Lucas and Brian De Palma but while he shares the first two's instinct for showmanship, he's unencumbered by Spielberg's emotionalism and Lucas's self-importance. He has more in common with De Palma - both are mischief-makers and gifted stylists.
Zemeckis was born in 1952, and grew up in a blue-collar household on the south side of Chicago with parents who were mostly uninterested in cinema, or any other culture outside TV.
Petit's World Trade Center walk took place the year after Zemeckis graduated from the University of Southern California's film school, but the young wannabe director missed it: he'd won a writing gig on the cop show McCloud, and had so immersed himself in work that "I was oblivious to everything that was happening in the world at that point, including the stunt".
He uncovered the story while reading about the Twin Towers in the aftermath of the terrorist attacks of September 11 2001. Immediately, he went in search of footage, but couldn't find any, because none exists.
"Philippe was on that wire for 45 minutes, and in the entire city of New York, no one was able to scramble a motion picture camera in that amount of time and record a moving image of him," he marvels. There are photographs of Petit on the wire, shot by one of his accomplices and widely seen, most recently in the Oscar and Bafta-winning documentary Man on Wire. But no piece of cinema shows Petit's coup in motion. So Zemeckis decided to make one.
Joseph Gordon-Levitt stars as Philippe Petite in The Walk.
He met Petit in 2006, and talked to him for hours about how he pulled it off, and why. The how was complex, and the why proved inexplicable. "I realised it's like asking any artist, 'Why did you paint that painting?"' he says. "It's a ridiculous question, though it's one that everyone wants the answer to. But the point is the painting."
What Zemeckis did work out was that from the moment Petit realised the walk was theoretically possible, he felt an obsessive need to make it happen. "I completely identify with that," he says. "You just have to do your art. Nothing can stop you." For Zemeckis, using new technology is a kind of artistic duty, and he describes The Walk as "the culmination" of his career to date, in terms of its spectacle and spirit.
It's easy to see how his 1978 debut feature, a scrappy comedy about six young Beatlemaniacs called I Wanna Hold Your Hand, led to the blackhearted satire of Used Cars, which so impressed Michael Douglas that he insisted Zemeckis, then 28, should direct Romancing the Stone, a swashbuckling rom-com that needed a rascally touch.
That film, in turn, was so successful that a script that Zemeckis and his then-writing partner Bob Gale had been shopping around since the early 80s was instantly snapped up by Universal. It was about a teenage boy who travels back in time and is seduced by his mother.
No one thought that Back to the Future would work. Disney passed on it "specifically" because of its incestuous plot, says Zemeckis with a twinkle, while the other studios thought it was "too soft": they saw it having mileage as an outrageous comedy in the style of Porky's. He wouldn't dare pitch the idea nowadays, he says, because "the sophistication of the audience has regressed", and the film would "never" be made as PG-rated family entertainment.
It's notable that Zemeckis, with his ready embrace of digital technique, has never felt the need to tinker with Back to the Future or its two sequels - unlike Spielberg and, more notoriously, Lucas, both of whom have meddled with their earlier work. (Lucas's heavily adjusted Special Edition remixes of his original Star Wars trilogy are now the only freely available versions of those films.)
Director Robert Zemeckis on the set of The Walk.
"Oh, I think that's an abomination," he says, when I ask why. "Go back and 'fix the flaws?' Why would you do that?" Well, Lucas has used it to more or less overhaul his best-known work to his apparent satisfaction, I say. "Yeah, I don't know why he's doing that," he says, with a sardonic look.
"And didn't Steven [Spielberg] replace the agents' guns in E.T. with walkie-talkies?" he continues. (He did indeed, for its 20th anniversary re-release.) "What's the point of that? Back in 1982, it was OK for a family film to show children and guns in the same frame. Isn't that important?"
Does he see it as dishonest? "Yeah. To me it's like colourising a black and white film and then refusing to let people see the black and white version. To do it just because you can... I don't understand it."
He's similarly testy when I bring up the much-discussed prospect of a Back to the Future remake. (The trilogy must be one of the only major 80s pop-culture properties to remain untouched by Hollywood.)
"Oh, God no," he groans, when I ask him if he'd ever consider signing off on it. (Zemeckis and Gale's original contracts give the two men final say on the production of any Back to the Future-related films.) "That can't happen until both Bob and I are dead. And then I'm sure they'll do it, unless there's a way our estates can stop it.
"I mean, to me, that's outrageous. Especially since it's a good movie. It's like saying, 'Let's remake Citizen Kane. Who are we going to get to play Kane?' What folly, what insanity is that?"
I'm still struggling to work out what actually impresses Zemeckis. His answer takes the form of a story about a preview screening of Jaws in 1975, which Spielberg had invited him to while he was still a jobbing writer. Afterwards, Spielberg discussed the audience reactions with him - he had been recording them at every screening, then fine-tuning the film to maximise communal screams and whoops - and mentioned one troubling moment: a lone voice cheering during Robert Shaw's blood-spluttering death scene.
Zemeckis confessed it was him. "I was cheering the magnificence," he says. "It was just so brilliantly done that I couldn't resist."
What was the first time he remembers feeling like that in the cinema? He barely has to think.
"Dr Strangelove," he says. "Slim Pickens riding the atomic bomb." It's an outlandish, frightening scene, yet it's also an uproarious pleasure. If Stanley Kubrick hadn't shot it in 1964, Zemeckis would have done by now.
Who: Robert Zemeckis (pictured) directing Joseph Gordon-Levitt What: The Walk When: In cinemas from October 22
