There aren’t many writers so prolific that adaptations of their work could be seen as a genre in their own right. Stephen King had his first novel, Carrie, published in 1974. The Brian De Palma-directed film adaptation was released in 1976, and filmmakers have been adapting his novels, novellas, and short stories ever since.

I think one of the reasons for King’s immense cultural stature is the distinctive tone of his works: folksy, grounded in small towns, and liberally soaked in an earnest sense of Americana, they typically portray aggressively mundane and ordinary characters thrust into extraordinary circumstances. They generally fall into the horror genre, with a number in crime or fantasy, but for me at least the essential “Kingness” of the writer at his best is his handle of ordinary but interesting people in harrowing and imaginative situations.

The best screen adaptations of his works follow in the same vein: those that focus on and embrace the richness of his characters stand out, while those that focus on the fantastical or horrific elements tends to fall by the wayside. A select few can be considered to be genuine film classics, and the thing that unites them is their emphasis on King’s strongest gifts as an author. Obviously opinions will vary, but if pressed to name the very best Stephen King adaptations the list would ultimately go like this: Stanley Kubrick’s The Shining (1980), Rob Reiner’s Stand by Me (1986) and Misery (1990), and Frank Darabont’s The Shawshank Redemption (1994), The Green Mile (1999), and The Mist (2007).

To that list of six films I would now add a seventh. Francis Lawrence’s The Long Walk, adapting King’s 1979 pseudonymous novel of the same name, is an outstanding achievement. As a bleak dystopia it seems flawless. As a confrontational thriller it feels close to traumatic. As historical allegory and cultural satire it is smart and intensely relevant. Most of all, as a showcase of King’s classic ordinary characters in extremis it is a bona fide masterpiece. I do not typically apply star ratings to my reviews, but rest assured this is five-star stuff. This is the feel-bad movie of the year.

In the aftermath of war and economic depression, America holds an annual ‘long walk’. Each year 50 volunteers, all young men, are selected to march down a deserted country road. They must continue walking, at a minimum pace of three miles an hour. If they drop behind, they receive a warning. Failing the third warning results in a bullet to the head. The last boy to finish wins a fortune in money and an unlimited wish. The other 49 boys are dead.

There is a boldness to Francis Lawrence’s adaptation in that, a few key flashbacks aside, the entire film consists of the walk. The boys start walking within minutes of the film beginning, and the end credits rolls within minutes of its end. A lesser director might flinch, fearing that without changes in character and scenery the film would be boring. Lawrence smartly trusts the source material and his cast, and the result is something that is both riveting to watch and emotionally rich. You never leave the characters, and that enriches the effect their ordeal has on you.

An interesting combination of characters are spectacularly brought to life by a hugely talented cast. Cooper Hoffman and David Jonsson share the lead as Ray and Peter, who meet and befriend each other during the walk, and are an enormously engaging double act. The other walkers are all fascinating and unexpected characters played impeccably, whether Garrett Wareing as the moody Stebbins, Ben Wang as the amusing Olsen, or Tut Nyuot as the faith-driven Baker. Charlie Plummer stands out as Barkovich, a character whose narrative shifts in unexpected and troubling ways as the film progresses. Judy Greer stands out in a small but pivotal role. Mark Hamill delivers something iconic as the anonymous “Major” who oversees the walk. Always a smart performer, he zeroes in on his character’s purpose and identity and delivers something that is right on the money.

It is a blunt and horrifying film. The violence punctures the film at regular intervals, and is deliberately bloody and confronting. It needs to be. It informs the characters and drives the plot. It emphasises the underlying allegory at work. King clearly had a social context in mind when he wrote the novel, and JT Mollner’s screenplay observes it. The film is also wide open for new and contemporary interpretations, some obvious and others more subtle.

The Long Walk has taken a long, difficult road to the screen. It took two years for Carrie to become a film. It has taken 46 years for The Long Walk to join it, but rarely is a film so worth the journey or the wait to see it play out with such depth, careful observation, or humanity. This is must-see cinema; don’t wait for streaming.