If you want a short cut to a lasting friendship, get yourself on a film crew in difficult practical conditions. Apart from the accepted hierarchy in place, you're all somewhat dependent on everyone else and to a degree, that equalises people. You share experiences that 'normal' people don't usually have access to and you face problems together that you'd not usually encounter in 'real life'. I led a five-crew, six-week shoot in relatively easy conditions in Africa a while back. The result was a lasting friendship with each and a marriage. We all agreed that something rather extraordinary happened between us all and it remains my most thrilling and profoundly powerful professional adventure. Well, director Iñárritu and his crew were filming for (on and off) eleven months in some of the most inhospitable conditions it was possible to find on the planet. I imagine great friendships were forged. Steven Spielberg, upon recognizing a Jaws crewmember will happily reminisce, still treating the experience as a bonding one, war stories if you will. Yes, there were a few who were not up to the conditions (I suspect it was a little more than 0.1% unless he had a crew of a thousand and only one departed), and there were those who didn't gel with the director's way of working and that happens but what Iñárritu has crafted in The Revenant is astounding whichever way you approach it, friend or foe.

The most unbelievable aspect of The Revenant is (drum roll) the fact that the story is based on true events. The title refers to someone who returned, supposedly from the dead. With the exception of finding the true story hard to believe, you are never in any doubt about the reality of what you are looking at. The movie makes you feel almost everything; from crawling, severely wounded across the snowy wastes, to eating things other starving men would sooner die than eat. You feel every rib cracked inhalation, every piercing bite of the wind and the glorious respite of an open fire in the frozen wastes. You appreciate the things we take for granted in profound ways watching this film. You feel the stench of rotten flesh (yes, feel it) and the literally visceral act of slipping into the dead body of a horse to keep warm. Let's leave the dagger and axe plunges, gunshot hits and arrow strikes aside for the time being. Everything about this movie is deeply felt and that's the work of a master filmmaker. We'll get on to the contribution of his actors and crew a little later. Would this striking communication of immediate sensation have been the same if shot in a studio with green screen and hot coffee and Danish pastries on a table nearby? It's the question Iñárritu had to ask himself and he came up with the answer "No," which I would believe wholeheartedly if I'd not been so impressed with Everest. I knew that there were many scenes in Baltasar Kormákur's extreme movie that were shot in a studio (for control over base camp and the more hair-raising stunts) but it had me fooled and I'm no slouch spotting these things. I should say I used to be no slouch. I am now officially taken in by film craft and it feels fine. Given what is possible on a soundstage, it does seem a little over the top to go to these hazardous places and set your (A-List) cast down in the real, punishing outreaches. But what dividends! The Revenant is a triumph of seemingly old-fashioned movie making with the significant advantages of what is technically available and doable in 2015 (but we'll get to Baloo in a paragraph or two).

I'm sure Liam Neeson would agree (he's not a green screen fan) that actors respond better to stuff that's really there than stuff that isn't. When he shot The Grey, he was stuck in icy conditions shooting in British Columbia. If the wolf behaviour wasn't strictly realistic, everything else was; same with The Revenant with bells on. When you're not being stunned at the available light aesthetic, the elastic cinematography – cameras in places they have no practical right to be, moving in a way that seems impossible – you have to conclude that the actors were inches from the wide angle lenses in a lot of the shots. Stars and co-stars alike are shot in extreme conditions in huge close ups. You can almost see the hairs on the legs of the fleas in DiCaprio's beard. This gives the film an urgency and immediacy that standard close ups, wide shots and long shots standardly intercut cannot give you. The pre-assumed CG avalanche is shown via a mid-shot of DiCaprio, a throw away almost and yet, it was, according to Iñárritu, a real avalanche set off by the crew. Reviewer picks up jaw, wanders out into the street in a daze... I hate buzzwords but if I see another film as 'immersive' this year I will be shocked out of my pantaloons. Iñárritu's long flowing shot style means the editor seems to have little to do (I know this isn't true but hey,) but editor Stephen Mirrione's work on the many dream-like flashbacks and hallucinations that pop up in to DiCaprio's subconscious every now and again are beautifully put together. Rhythmically, Mirrione's work is that of a master music editor strikingly interpreting the work of a composer of immense talent. Iñárritu's sense of cinema feels (there's that word again) like it's totally instinctive. He's helped enormously by his sensitive and gifted magician of a cinematographer, Emmanuel Lubezki.

The true story of trapper Hugh Glass (played by a superb Leonardo DiCaprio) is easy to summarise. In a hunting party, while scouting for game in 1823, Glass came between a grizzly and her two cubs. Let's just say, it didn't go well. Killing the bear with help from fellow trappers (in the movie, he's alone), Glass sustained horrific injuries; a broken leg, exposed ribs from bear slashed flesh on his back and many festering wounds. Abandoned by the two left to bury him after he succumbed to his injuries, he found the strength to claw his way to semi-health setting his own leg and letting maggots on rotting logs eat his gangrenous flesh. He was helped by friendly Native Americans along the way and eventually got to where he wanted to be, 200 miles from the site of the bear attack. It seems mean spirited to say any more. Iñárritu and co-screenwriter Mark L. Smith maintain the basic structure of Glass' story but crucially, for drama's sake, they give Glass another stronger reason for revenge – a murdered son (Forrest Goodluck). Glass's fictional flashbacks illustrate a raid on his home village in which his Native American wife is slain and his son burned. There are some searingly powerful images in these flashbacks, not least the one with Glass's wife literally suspended over him, her smock billowing around her, floating like the blue man in the Chagall. His son, Hawk, with a burned and scarred face is free-spirited and loving. He stays with his wounded father who is trying to instill in him a strong sense of self-preservation in a world where skin colour is the polarising tribal call to arms or a falling into welcoming ones. While suffering from his injuries, Glass is helpless as fellow trapper Fitzgerald (Tom Hardy) attempts to suffocate him, an act that leads to Hawk's murder... It's revenge for this one act that drives Glass and the movie forward.

The performances are all top notch. You never get the impression that you are seeing a bunch of actors mucking about in the snow. The reality of the performances is skillfully threaded into place, a cold and unforgiving place. Domhnall Gleeson has shrugged off the great coat of the less than exciting General Nux in Star Wars: The Force Awakens and takes the bit in his teeth playing Captain Henry with some relish. It's such a different role from anything he's done before, so kudos to the director and especially to the actor whose boyish charms are completely hidden, stamped down to enable him to be ruthless but moral in a very hostile world. Oh, and the beard helps. Tom Hardy is an actor for whom I have great respect. Despite being underwritten in what promised to be his movie, not Charlize Theron's in Mad Max: Fury Road, his recent performances have all been those of a character actor that everyone seems convinced will eventually emerge as a star. I'd really like him to stay as a character actor. I'm not sure anyone has seen 'Tom Hardy' on screen yet – perhaps his Inception part was a little closer to who he really is but then again, with chameleonic Hardy, how would we know? His Fitzgerald is a self-serving, murderous, cowardly bastard who volunteers to stay behind with Glass's bear-shredded body because the money was too good to turn down. All he has to do is wait until the hunting party is far enough away and then kill Glass and move on. Problem is, he has two youngsters with him desperate to do the right thing. Hardy is never less than extremely menacing always slyly arguing his side and mostly winning. The only downside was his use of an accent (geographically and historically accurate no doubt) that made a few words more than a little unintelligible though let's not bring up Bane in The Dark Knight Rises.

But trying hard not to jinx his award chances at all, the film is carried on the gashed and suppurating shoulders of one man. Leonardo DiCaprio went the other way in terms of an acting career. Yes, he had a few roles as a character actor but then became a heart-throb 'star' drowning in front of a floating Kate Winslet and has tried to stay true to his character actor roots ever since despite the 'leading man' box he's been forced into. He has proved himself time and time again as an actor of rare charisma and despite his good looks and tall frame, he has managed to convince in all of his roles. Like Jeff Bridges, you could describe DiCaprio as a character actor trapped inside a leading man's body. Well, that body came in for some stick in The Revenant. All power to DiCaprio for inhabiting Glass so consistently and so convincingly. There's not a false note in his entire performance and as I mentioned earlier, he makes us feel every twinge of pain, every shoot of agony, every muscle strain of effort. This alone (sans dialogue for the lion's share of the film) should put him in with a great shout at anything the US and UK Film Academies choose to throw at him.

I want to share one brief moment in the film that, after it was over, left me breathless with admiration and still (crucially) totally involved with the characters and drama (no, not Paddington's attack just yet). Glass has stolen a dead friend's horse and hightails it away from a small tribe of Arikara Indians who want to kill him. The horse, arrows piercing its flank, jumps for its life and to its death off a cliff (total shock) while Glass smashes into a fir tree that presumably breaks his fall and not his bones. From the long shot of Glass on the horse to the aerial of the fir tree that broke his fall is a single shot which by all the laws of physics seems an impossible achievement. OK, we are used to impossible shots now because we are used to digital manipulation but whatever we think we know can be done doesn't mean it has been done. In this one scene as in the whole movie, you never question the veracity of what you are seeing even though there's a part of you being constantly bamboozled and you don't know how. The fact that we are able to stay on Glass as he gallops away puts this shot into the 'WTF' area of cinematic appreciation. I'm not going to ask how. I'm just going to love the fact I was still emotionally engaged regardless of my geek subconscious baying to the heavens "How the fuck did they do that?" If I am asking that question, ninety-nine times out of a hundred, I'm out of the movie. It's a rare film indeed that tells its story so powerfully, via mysterious means and still keeps me caring.

Speaking of which, let's now settle into the defining moment of the film, the scene that made everything that followed a direct reference back to that moment. I have touched upon this part in my article Believe It Or Not, extolling the virtues of special effects done for real. Well, despite what many may think after seeing this scene, the grizzly is a true wonder of modern digital film visual effects. Rupert is not trained. Pooh is not declawed or de-toothed. The bear is not there at all. The bear is actually stuntmen giving Leo a hard time and wire workers pulling the poor bastard all over the forest floor for weeks. I have at my disposal the eyes and opinion of a seasoned natural history filmmaker. She pronounced the bear very good but still was tipped off by some nuance of weight-based movement. I asked her that if she was not pre-informed that it was a stunning digital creation, what did she think? She said she would probably be fooled. That's high praise. The bear effect in The Revenant had to be utterly believable as it sets off the chain of events of the whole movie. And, by Christ, it is. I applaud the filmmakers for keeping quiet on its creation. It really is still utterly believable even if you know how it was done. Never was belief suspended as artfully as this bear has managed. God knows how realistic it'll seem to those not versed in visual effects. I wish I could single out a name to praise but I suspect it's the work of hundreds of digital artists. To those responsible at ILM, I salute you all.

Finally, I'd like to mention a few things that stood out ending on a credit that made me howl with mirth. As you may have guessed, The Revenant is not a laugh-a-minute experience. At the very beginning, after a few DiCaprio dreamtime shots, we start moving up a flooded forest. As we go forward, we tilt up and the trees become visible. Then as the first human leg breaks into frame right, it feels like giants invading. It's only a few seconds later that you realise the trees must be saplings or youngsters. The trompe l'oeil may not be intentional but it's interesting all the same. There's a scene of a hunting party in the dark and the red glow of the party's lights play on the tree silhouettes and for a few seconds, the screen looks like a red velvet theatre curtain twitching to open. I almost imagined the score at the time 'tuning up' to complete the illusion. Iñárritu and his editor have the sense or adherence to an overall directorial scheme to leave bits of 'real' reality in the cut that a lot of other filmmakers would excise. DiCaprio mounts a horse in the latter stages of the movie and with his up swinging boot, it appears that he catches another horse in the nose. It's subtle but it's there. DiCaprio takes off his bear claw necklace to give away and because of his wardrobe and general state, the necklace does not come off cleanly. It's stuck in his hair, his bearskin and for one brief flash, I thought I saw DiCaprio's real frustration leaking out. It was the only time I thought of him as Leo and not Glass. The haunting music score is simple, sombre and restrained, a lone cello evocatively played with a small orchestra behind it. It has great emotional depth despite (or because of?) its simplicity. The great Ryuichi Sakamoto gets top billing with Alva Noto and Bryce Dessner also credited. Finally, that credit I mentioned... DiCaprio, even before the bear attack, does not give the impression of man who takes good care of himself. Personal grooming goes out of the window ("Because he's not worth it..."), hair gets lank and filthy and beards grow. Now if he forgot about grooming before the bear attack, you can damn well be certain he's not going to pay it any mind once his survival is under threat from disease and general injury. He does wash his hair in the movie (no product, just two handfuls of water) but that's really it. The credit that floored me was the following:

Personal Hair Stylist To Mr. DiCaprio – Kathryn L. Blondell

I just kept imagining Iñárritu's direction "Kathryn, make it a little more lank on the scalp, greasier overall... Yeah, that's good. Rub some blood in, yeah... Got any of that horse's bile? Bit more of that, yeah, the green stuff... Yes, I know how bad it stinks. Leo won't mind."

The Revenant is a work of immense passion from a filmmaker whose drive for realism seems to eschew any form of comfort. Gripping, brilliantly acted and directed with a sleight of hand that should be impossible but never feels like it is, you'll not find a film anything like it this or last year. As the rebooted Bond's second victim says in Casino Royale, "Made you feel it, did he?" Oh, yes... Very much so.

Post Script: After the triple whammy of Best Film, Best Leading Actor and Best Director at the Golden Globes this week, the omens are good for continuing a run of success. May the movie gods smile on Alejandro G. Iñárritu and crew.

*http://www.theguardian.com/film/2016/jan/03/alejandro-gonzalez-inarritu-interview-the-revenant