What would it be like to summit Mount Everest? Even in this post-Hillary, commercialised world, where the opportunity is there for anyone of sufficient physical capabilities (not to mention a hefty bank balance), a mythical halo still engulfs the Tallest Mountain On Earth.

I have a sneaking suspicion it’d be deeply disappointing. Not necessarily the experience of standing on the summit itself – the anticipation and the physical ordeals preceding that moment would have to ensure it’d be a wee-bit transcendent – but rather, the comedown. Imagine plodding down that slope, cognisant that, in all likelihood, you’ll achieve such an accomplishment again. Your life would be neatly bisected into BE (Before Everest) and AE (After Everest), reduced to a series of awkward social encounters where you carefully manoeuvre the conversation towards climbing so that you can ‘casually’ boast about That Moment.

Baltasar Kormákur reportedly wanted to film Everest, an adventure-slash-disaster film drawn from real-life tragedy, on the mountain itself. Cooler heads prevailed; aside from some footage taken at Everest Base Camp, filming was completed on a range of other (smaller) mountains and, naturally, in the studio. Yet, narratively at least, Kormákur and screenwriters William Nicholson and Simon Beaufoy have produced a perfect facsimile of their titular mountain: there’s a challenging, overlong ascent; a spectacular summit; and an inevitably disappointing conclusion.

Okay, “challenging” and “overlong” are a tad harsh. The flabbiness of Everest’s first act is entirely understandable. It has to introduce a substantial cast. There’s…

Jason Clarke as Rob Hall, a well-respected mountaineer and owner of expedition guide company, Adventure Consultants.
Keira Knightley as Jan, Rob’s wife, packing a pregnant belly and a questionable attempt at a Kiwi accent.
Jake Gyllenhaal as Rob’s bearded, good-natured competitor.
Josh Brolin as Beck, a brusque, entitled yet experienced climber.
John Hawkes as a weedy mailman determined to make the summit on his second attempt.
Naoki Mori as Yasuko, the only climber who’s also a lady.
Emily Watson as a sort of base camp den-mother. Sam Worthington as Sam Worthington over there somewhere.
Elizabeth Debecki as a very tall person. Robin Wright as angry Texan wife lady.
Michael Kelly as important journalist who undoubtedly will make it out alive because someone had to write about this.

In addition to juggling this formidable cast – most of whom get enough lines to at least sketch the outlines of a personality – Everest has to provide enough particulars about commercial climbing circa 1996 to engage an uninformed audience without dipping into banal overexplanation. It gets the balance right, for the most part, but with this many balls in the air it’s competent rather than entertaining.

The focal point for all this dense storytelling is Rob, lent an easy gravitas by Clarke’s assured performance. You believe he’s the sort of man that could have summited Everest multiple times (when the movie begins, he’s reached the top four times). The screenplay is carefully constructed to ensure that you regard Rob as trustworthy and good-natured. He’s a confident climber, yet he’s respectful and considerate of his less proficient clients. He’s generous; we learn that he gave Hawkes’ character, Doug, a substantial discount (though we also learn that his per-person fee is a steep $65,000). When the increasingly crowded path up the mountain causes animosity at base camp, he’s the first to suggest a system to avoid queuing delays, ultimately negotiating a mutually-beneficial relationship with Gyllenhaal’s character.

So far, so standard. What’s clever about this, though, is how it enables the film to subtly undermine Rob’s authority having established him as a paragon of reliability. As the fateful day approaches – and whether or not you’re familiar with the backstory, the fatefulness of said day is unmistakable – Rob begins to make decisions that, on the face of it, are questionable. He pushes ahead with plans to summit despite an impending storm. He instructs his employees to rush in their attempts to rope up the precarious Hillary Step. He accompanies Doug to the summit – far past the scheduled turn-around time. Because we’ve been conditioned to treat Rob’s decisions as true and correct, it takes a while for it to sink in that his judgement may not be as flawless as we first thought.

By the time we’ve figured that out, of course, the film has switched from adventure thriller to a kind of disaster procedural, unpacking in ghastly – and theatre-shaking – detail how a handful of small mistakes can lead to a devastating result. As a cinematic experience, it’s momentous. The sound design is bone-rattlingly effective and the 3D effects draw you right into the action (I say this as an avowed 3D sceptic). The emphasis here is not on spectacle though, but humanity;  Kormákur’s camerawork is deific, swooping in from a distance and surveying his ill-fated mountaineers with detached empathy (note that even when they reach the summit, we never pause to take in the view).

The film’s final act is disappointing. Perhaps this was inevitable; the descent will never live up to the giddy highs of the peak, after all. (Including the worst bit of product placement doesn’t help, either – thanks Gatorade!) But the film’s reluctance to follow through thematic shift signalled by Rob’s series of (minor) mistakes suggests its cowardice. Emily Watson’s character frets on the initial assent to the summit not because of any fear of loss of life – but because their business will suffer if their clients don’t reach the top two years in a row. A better film would have followed through on this, would have unambiguously indicted the cumulative commercialisation of the mountain.

Instead, Everest descends into maudlin emotion. The rigorous specifics that made the second act so gripping melt into an avalanche of grief and despair. I don’t mean to belittle this – it’s understandable and the film has certainly earned this grief. Yet, there are so many missed opportunities that keep Everest from attaining the greatness it strives for. Maybe I’m more sensitive to this after Sherpa, but the relentless marginalisation of Sherpas here came across as egregious, particularly when they played a large part in an (aborted) rescue attempt that could have featured far more prominently. Equally, the screenplay’s balancing of the disparate fates of Rob and Beck is unnecessarily jarring; whether a result of last minute editing or not, the film struggles to maintain emotional coherency juggling these two storylines in its final minutes.

Whatever its failings on the downward slope, there’s enough majesty in Everest’s peaks to justify an expedition. Just make sure it’s in a big theatre with a great sound system.