For those of us with no particular head for heights, the documentary Free Solo risks being the most unwatchable must-see in years. Its subject is one Alex Honnold, the young American superstar of free solo climbing, whose enthusiasts (madmen might be a better term) delight in scaling sheer rock faces without ropes or safety harnesses, wearing instead but a bumbag full of grip-friendly chalk that will clearly be of no use whatsoever should the climber slip and plummet to a horrible death. A prologue flaunts Honnold's achievements in spidermanning his way up one- and two-thousand feet peaks; now, we learn, he intends to shimmy up the 3,000ft El Capitan in the Yosemite mountains. Of all the films that were in the running for this year's Best Documentary Oscar (which Free Solo eventually won), this was the one with the most easily grasped spectacle and stakes. It's a tiny, hard-bodied Californian dude - a latter-day Harold Lloyd, with a hoodie in place of a boater - pitting himself against nature, with no safety net or any other back-up plan; it is, quite simply, climb or die.
Nonetheless, Free Solo offers this daredevil the prospect of a softer landing, and in doing so, the film opens up a new narrative front. Early on during filming - during the initial preparations for the El Capitan climb - Honnold made a match of some kind with one Sanni McCandless, a perfectly sane, necessarily peppy San Franciscan he first met during one of his book signings. Our climber is at first noncommittal, muttering to the crew that McCandless is "trending towards girlfriend", yet soon Alex, hitherto a confirmed bachelor - who apparently lives out of a camper van, owns one shirt and eats his chilli direct from the pan with a kitchen spatula; who would, perhaps, be deemed entirely basic were it not for his tendency to haul himself over mountains - finds himself with a woman other than Mother Nature drifting in and out of his mind. That Honnold is probably not the easiest catch can be gleaned the moment he turns to the camera to wonder aloud why the minute he takes up with someone, he picks up an injury that grounds him; or from the later episode in which - bluntly, without much in the way of feeling - he bats away Sanni's concerns around a hobby that might, you know, kill him. (You may have flashbacks to Morgan Spurlock's poor better half in Super Size Me.) From wondering whether free soloing is really worth the risk, we might pivot to pondering, as Sanni surely has, another issue: is he worth the risk?
You will form your own opinions on Honnold, what he does, and whether the monomania that sees him return to an indoor climbing wall mere days after breaking an ankle is endearing or somewhat closer to batty. (Nothing will stop him, it seems, except gravity.) It would be possible, certainly, to imagine a chilly Werner Herzog study of Honnold, one that omits the lower-case romance in favour of the Romance of man throwing himself up a hill, much as Herzog's Woodcarver Steiner threw himself down. The Free Solo we have was compiled by the climber's entourage, however, which explains its broadly genial tone, and also why it sometimes seems to enable its subject, cheering him on to reach the heights that might also elevate the movie. Occasionally, Jimmy Chin (who shares the director credit with Elizabeth Chai Vasarhelyi) will appear on screen to voice some fleeting doubt, and there is the passing suggestion that Honnold has been pushed to these extremes out of a desire to impress the late father who belittled him as a child. (Tellingly, the filmmakers dig up a photo of the young Alex clinging to his tall-and-broad pop's leg as he now does rockfaces.)
Yet there remain a number of questions that aren't asked and answered before we strap ourselves in for the nervewracking final ascent, and Honnold himself is allowed to shrug off a lot of reckless behaviour as the movie tells us Alex-is-as-Alex-does. Take the spectacle out of the equation, if that's at all possible, and free soloing begins to resemble the kind of selfish act only a certain type of affluent white male - someone who doesn't have to work for a living - gets to carry out, something done by himself for himself. (Locked into his obsessive routefinding, his need for dominance and control, there isn't even much sign Alex gets to enjoy the views.) I should perhaps offer my fellow jitterers the reassurance that, at the time of writing, Alex Honnold is still alive - yet even armed with that knowledge, it would be possible to be conflicted indeed about Free Solo's achievements. When he could bring himself to look, this viewer found himself torn between astonishment at what the film shows (and how it shows it to us, climbing in parallel with Alex to hone in on the microscopic movements of hand and foot that stick him to this mortal coil) and frequently wanting to scream "you're a fucking lunatic" at the subject it frames in generally heroic terms.
Free Solo will be available on DVD through Dogwoof from Monday.