Unlikeable, impassive, Cillian Murphy’s J. Robert Oppenheimer is a muted presence in a big bang movie. Thankfully, Christopher Nolan articulates Oppenheimer’s personality and sometimes his science through cinematic sound and vision.

At three hours, Oppenheimer harks back to the major movies of old with a cluster of cameos, many of them British. Some occur incidentally only to return to perfect effect, propelling the plot. It’s an example of Oppenheimer’s precision-construction – mirroring the complexity of the politics and physics.

Adapted by Nolan himself from the book American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, the film unfolds in three intercutting storylines. Oppenheimer’s rise from student to ‘father of the atom bomb’ is the straight-route to the blast. A post-bomb, anti-communist hearing is claustrophobic and Kafka-esque. A monochrome third strand sees Robert Downey Jr’s Lewis Strauss seek confirmation as a senator, scrutinised for his connections with Oppenheimer.

Oscar-worthy Downey Jr is scintillating as Strauss, the former director of the Atomic Energy Commission. Serpentine, smiling, he’s the epitome of the self-made businessman and politician. Nailing it live-wires the movie because Oppenheimer’s film is more about people than particles. People made the bomb, took the decisions.

The film’s wordy but fabulously shot. Show-not-tell wins the day. At the after-party for the bomb-drop on Japan, Oppenheimer’s hailed by his colleagues and forces a smile but sees only a room full of charred bodies and flakes of ash.

Matt Damon is pitch-perfect as Lt-General Leslie Groves, the military leader of the project, getting the funniest lines, full of bulldog bravura. Emily Blunt seems wasted as a background wife but true to Nolan’s switcheroo, returns to deliver a knockout moment. Best not to name-drop the cameos – spotting them is part of the fun.

Only Florence Pugh is badly served. An actor of her ability is more than capable of portraying fractured sensuality without the need for repeated nudity, counter to the subtlety of the film. It’s the only misstep.

As tightly constructed as the bomb itself, Oppenheimer’s intricacy is immersive and impressive. The soundtrack – crackling like a Geiger counter – is unsettling and primal, but not as effective as Hans Zimmer’s for Nolan’s Dunkirk.

Rather, Oppenheimer’s tension comes from the collision of politics and personalities, building to a screw-tight finish, and finally – thanks largely to Downey Jr - to an emotional payoff.

See it on a cinema screen. Shot partly in IMAX 65 mm, even the biggest TV screen won’t do it justice. More intelligible than Tenet, as involving as Inception.

Cinema can sometimes take strange turns. And the Barbenheimer phenomenon is not one cinephiles would have been pegged as a cinema-saving moment at the start of 2023. Yet in a release calendar filled with bloated, expensive sequels and the latest on the conveyor belt of superhero multiverse messes, Barbie and Oppenheimer’s arrival feel like a breath of fresh air. Both are celebrations of American ingenuity but also a warning of the forces that can be unleashed by them (by men), and both represent exciting works from two of the very best directors currently working.

Oppenheimer tells the story of the creation of atomic weapons, the circumstances that led to it and the path they set the world on after their use. And it all focuses on the titular figure, the father of the atomic age, J. Robert Oppenheimer.

In the lead, Cillian Murphy gives a turn that fulfils the promise he has shown throughout his impressive career. His Oppenheimer can be a charming chameleonic man, manipulating people around him with wit and insight. But then the weight of what he has been a part of flashes across Murphy’s face, the haunted look he has lingers and infects the audience with it. Surrounding Murphy is a cast stacked with talent, and there is not a weak link in the mix. Matt Damon is briskly effective and pugnacious, Emily Blunt bristles with a righteous fury, Florence Pugh somehow leaves an impression within a narrative that gives little for its female characters to do. Across an entire ensemble many get moments to shine. But perhaps the two most impactful supporting turns were David Krumholtz and Robert Downey Jr.

As with all his works this is a quintessentially Nolan piece. And it may well be his greatest achievement. Nolan’s style is an abrasive one, at its worst drowning his films in sound and fury so much that the narrative ends up signifying nothing. But this is not the case here. The style enhances Oppenheimer’s story, drawing the audience into his internalized perspective with a soundscape and visual language that sometimes threatens to overwhelm the viewer. But where it leaves the film is as a wrenchingly, impactful work, all the way to a gut punch of a final moment. For some it will be too much. But the devastation I felt for much of this runtime feels the point. I needed a hug from my partner. Oppenheimer will make you embrace your loved ones after hours of staring into the apocalyptic abyss.

On a technical level this film is remarkable. The authenticity of the design is captured by Hoyte Van Hoytema’s cinematography, which balances realism with more expressive or abstract moments. In an increasingly impressive body of work, Ludwig Göransson’s score is a beautiful, evocative work. And pulling this all together is Jennifer Lane’s editing, weaving together time and space, colour and black & white photography.

Don’t be put off by Oppenheimer’s run time. It moves at a terrific pace and rewards the viewer like few films have this year. Pairing a career best turn from Murphy and an auteur at the top of their game with Nolan, this is truly one of the masterpieces of 2023 and a cinematic must see.