VENICE, ITALY —
The high-altitude thriller "Everest", which opened the Venice Film Festival on Wednesday, should warn a lot of people off mountain climbing.
Gale-force winds, snowstorms, avalanches and deep crevasses
loom out of the screen with threatening reality in this 3D docudrama depicting a real disaster that killed five people on the world's highest mountain in May, 1996.
Icelandic director Baltasar Kormakur's epic stars Jake Gyllenhaal, Keira Knightley, Josh Brolin and Jason Clarke.
Michael Kelly plays Jon Krakauer, who was on one of the ill-fated expeditions and wrote the book "Into Thin Air" about it.
WATCH: 'Everest' movie trailer
Rival commercial climbing teams, who charged as much as $65,000 a head to take people to Everest's summit, got caught in a thunderstorm. Two of the team leaders, American Scott Fischer played by Gyllenhaal, and New Zealander Rob Hall, played by Clarke, were among the victims.
The others were Doug Hansen (John Hawkes), a postal worker from Washington State, the Japanese businesswoman Yasuko Namba
(Naoko Mori) and climbing guide Andy Harris (Martin Henderson).
Brolin plays the gruff Texas pathologist Beck Weathers, who had been left for dead in the snow when rescuers could not rouse him. He manages to get back on his feet, aided, the film suggests, by images that appear to him of his son and daughter and his wife Peaches (Robin Wright).
Weathers's evacuation at high altitude to hospital provides one of the most dramatic scenes. The pilot, after picking up the severely frostbitten Weathers, who later had parts of his right arm and feet amputated, launches back into the air by dropping the craft over the side of the mountain.
Kathryn Boyd and Josh Brolin pose for photographers upon the red carpet of the film Everest and the opening ceremony of the 72nd edition of the Venice Film Festival in Venice, Italy, Sept. 2, 2015.
Weathers also provides a thought-provoking answer to Krakauer's question why do you do it? Weathers says when he's not conquering a mountain it feels like he has a "black cloud" following him. When he reaches the summit "I feel like I'm reborn".
The film's most poignant moments are the conversations Hall had with his pregnant wife Jan (Knightley), arranged by Hall's base camp relaying his walkie-talkie transmission from high on the mountain, where he died after two days, to his home.
"I love you, please don't worry too much," Hall, whose hands and feet are frozen and who has run out of essential oxygen, tells his wife -- almost his last words.
The film makes clear that there is nothing glorious about the bravado of many who make the commercial treks to the top of Everest. Among them is New York socialite Sandy Hill Pittman (Vanessa Kirby) who is put out when she is told she cannot take her coffeemaker to the summit.
But it also shows how the dangers can force people who have come along for a thrill to rise to the challenge of saving their life -- like Weathers -- or lose it.