It begins with a small group of British soldiers walking through a seemingly deserted French town while pieces of paper declaring 'We surround you!' fall around them. Suddenly, shots ring out and they are sent running for their lives, scrambling over walls and through gardens until only one survivor, Tommy (Fionn Whitehead), emerges onto a beach alongside thousands of fellow troops waiting to be evacuated.

Meanwhile, across the channel, the Navy is busy requisitioning small boats from their owners to aid in the escape. But rather than hand his vessel over to the Navy, Mr Dawson (Mark Rylance) and his son Peter (Tom Glynn-Carney) set off on their own to provide help. And in the skies overhead, three RAF Spitfires, including pilots Farrier (Tom Hardy) and Collins (Jack Lowden), fly towards France to provide air support, despite the ever-present dangers of enemy planes and dwindling fuel tanks.

Despite the sheer scale of the production – which includes thousands of extras corralled on the Dunkirk beaches and a sizeable fleet of boats (including several surviving vessels that took part in the actual events) – Christopher Nolan's ninth film is no epic war movie. What he delivers is a more intimate film that focuses on the experiences of a small handful of people and, as the filmmaker himself says in one of the extras that accompany this Blu-ray release, tells their story 'as a thriller – as a Hitchcockian experience.'

What emerges is an incredibly tense piece of cinema. Dunkirk constantly ratchets up the tension to unbearable levels and rarely gives you time to breathe across its surprisingly compact 107-minute running time.

The film also delivers some truly astonishing aerial dogfights. Eschewing green screen effects, Nolan and his team make you feel like you're right up there with the pilots through a combination of having actors perform while being flown in a disguised two-seater Yak-52, and by mounting IMAX cameras on the actual Spitfires to provide the sort of immediacy and authenticity you get from GoPro footage (albeit with far greater visual quality).

So is Dunkirk Nolan's masterpiece, as so many critics claimed upon its cinema release? Not quite. The biggest issue is to do with the film's structure, which weaves back and forth between three perspectives, each operating across a different span of time – one week on land, one day at sea, one hour in the air. While it's certainly not hard to follow how they relate to one another, they just don't feel like they're playing out across such different periods of time, with Tommy's story suffering the most in this regard – rather than lasting a week, it ends up feeling like he just has an incredibly eventful couple of days.

Picture: As has been the case with all of his films since 2008's The Dark Knight, Christopher Nolan captured Dunkirk with two different types of cameras, resulting in a Blu-ray encode that switches between 1.78:1 (for footage captured by IMAX cameras) and 2.20:1.

Making up somewhere in the region of 70 per cent of the film, the IMAX material has a grand sense of scale to it that is aided by impeccable clarity and sharpness. These scenes also have a real sense of depth to them, lending the visuals a convincing sense of volumetric space within the frame. While it lacks the immediate wow factor of the IMAX footage, the 2.40:1 material also impresses from a technical standpoint, packing plenty of fine detailing into the image – even if it has a slightly coarser feel than the IMAX footage.

Our only real complaint is the heavy teal colour grading applied to the land and sea sections of the film. Not only is it rather monotonous, but it results in blue-tinged blacks.
Picture rating: 4.5/5

Audio: Dunkirk's DTS-HD MA 5.1 track is nothing less than a carefully constructed masterpiece of involving and immersive sound design. Constantly engaging the 360-degree soundstage, the mix has potent force and weight. Yet it isn't solely geared towards aural bombast, with more subtle touches (such as the constant rattling that surrounds you during the Spitfire cockpit scenes) providing some of the most effective examples of surround sound. Underlying all of this is Hans Zimmer's metronomic, ticking clock of a score, which keeps you on the edge of your seat.
Audio rating: 5/5

Extras: Given a disc of their own and split across five themed categories – Creation, Land, Air, Sea and Conclusion – this Blu-ray's 16 featurettes (with a total running time of 110 minutes) provide plenty of insight into the film's challenging production.
Extras rating: 3.5/5

We say: The soundmix alone is all the reason you need to pick up this wartime blockbuster on Blu-ray.

Dunkirk, Warner Bros., All-region BD BD, £25
HCC VERDICT: 4.5/5