Sam Mendes’ one-take wonder arrives in cinemas with less fanfare than some Best Picture contenders, but it is a superb piece of immersive filmmaking which unites its some-might-say gimmick and its narrative into a single indivisible whole. On the surface, there’s little here that’s new. The whole movie in one take idea has been seen before in versions both genuine (Russian Ark, Lost in London) and faux (Birdman) but arguably never before has it been deployed so ingeniously and so effectively. And, while no-one needs Sam Mendes or anyone else to tell us again that war is hell, it’s rarely been so realistically hellish as it is here. The banality of the pointlessly slaughtered cows in the French countryside is somewhat the point.

The set-up is perfect in its simplicity. Our heroes (George MacKay, Dean-Charles Chapman, both totally committed and convincing) have to cross no man’s land and get a message to the Devonshire regiment that they are waking into a trap. That’s it. Early on, I wondered just where the drama was going to come from. Either the information our two have about the German withdrawal is correct, in which case they will meet no resistance; or it’s wrong, in which case they will be diced by machine gun fire in two minutes. Either way, there isn’t a story. But Mendes and fellow screenwriter Krysty Wilson-Cairns have devised a remorselessly incremental series of obstacles which range from the purely natural, to collateral damage, to enemy action, to friendly fire.

And far from being a show-off-y gimmick, the supposed single shot presentation is vital. It means that there can be no cheating. As MacKay and Chapman set out, we’re going to watch every step they take, every breath they draw, every trap they blunder into, every adversity they triumph over. And when we desperately yearn to cut away, we can’t. There’s nothing to cut to.

In The Revenant, shot largely in long takes but including obvious cuts, several times I felt the style chafing against the story. As Iñárritu’s camera tracked along the length of a rifle barrel to move from one side of a conversation to another, I couldn’t help thinking – mate, you could just have cut there. Here, despite the overwhelming complexity of many of the set pieces, Mendes’ camera always seems to be in exactly the right place, and when something does move out of frame that in a conventionally-shot film, we would cut back to – the fact that it is out of frame becomes the point.

It’s also I think important to note that I never – and I use this word as precisely as I can – found the film exciting. Don’t misunderstand me. It’s never boring. It’s absorbing, terrifying, gut-wrenching, horrifying and suspenseful. But it never feels like a thrill ride. This is not James Bond. This is not Bourne. This feels real – even the parade of one-scene cameos can’t quite break the spell, although Benedict Cumberbatch comes close. Also, take a bow Colin Firth, Andrew Scott, Richard Madden, Mark Strong, Adrian Scarborough and Daniel Mays.

And there are moments of quiet beauty too. Hope, among the pain, and one moment which echoes the end of Kubrick’s Paths of Glory. And if this film isn’t quite as cynical as that one, then maybe that’s for the good too.

If there’s any justice, this will win Best Picture. It’s more personal and more epic than its closest rival in my eyes, The Irishman, although the bookies currently have it tailing Once Upon a Time in Hollywood and I haven’t seen Parasite yet. But if I had to vote tomorrow, this is what I’d pick.