Tom Hardy drives his BMW for 85 minutes, and the result is a tense, raw, entirely engaging film experiment.

If you make one mistake, one f-ing little mistake, the whole world crashes down on you.

–Ivan Locke

There’s a not-that-long, not-that-glorious tradition of the “one man show,” in which an actor and a director, often in a fit of hubris, attempt to hold an audience’s attention all by themselves. It tends to work much better on the stage than in the cinema. And recently, in the decade since Tom Hanks spent two hours talking to a volleyball, it seems like we’ve gotten one every year. Most of them have actually been pretty good:

• Moon (2009) — “Sam Rockwell on the moon”
• Buried (2010) — “Ryan Reynolds in a coffin”
• 127 Hours (2010) — “James Franco in a crevasse”
• All is Lost (2013) — “Robert Redford on a boat”

And now we have Locke, or “Tom Hardy in a car.” So yes, it’s a stunt. And certainly, writer-director Steven Knight — on only his second feature film, though his writing credits include Eastern Promises and The Hundred-Foot Journey — had his work cut out for him when he began this project. How do you keep the story moving? How do you keep a variety in the visuals? Who is the right actor to anchor this whole thing? Most importantly, how do you make your audience care about this character so they’re not even thinking about how much of a stunt this is?

Fortunately, Knight did two things extremely well. First, he wrote a remarkably engrossing screenplay, which economically builds up and weaves together over a half dozen characters in real time, while maintaining a strong emotional core. Secondly, he cast Tom Hardy as the title character, and the only one who appears on screen the entire run time.

Hardy is a remarkable actor with an incredible range — audiences best know him, of course, from the films he’s done with Christopher Nolan, as the smirking forger Eames from Inception, and then later as the hulking baddie Bane in The Dark Knight. But Hardy has shone brightest in smaller, less-glamorous productions: Bronson, Tinker Tailor Soldier Spy, and the very underrated MMA flick Warrior, in which Hardy plays the proud but deeply wounded younger brother to Joel Edgerton. It’s hard to remember that a (MUCH skinnier) Hardy first popped up in Band of Brothers and Black Hawk Down, too. Basically, the guy is versatile.

Ivan Locke is about as far away from Bane as you can possibly get. Ivan is a very deliberate man; he enunciates crisply; he makes the most of his luxury vehicle’s hands-free phone; he has a darling family; as a construction foreman he is respected, even beloved. The “best man in England,” someone calls him at one point in the film. All the same, Ivan is having a terrible night.

On the eve of the biggest job of his career — a concrete pour bigger than any in European history, we are reminded, save for nuclear and military projects — he has received a call that threatens to turn his carefully-managed life not just upside-down, but kicked over and stomped into tiny pieces. And aside from the film’s opening shots, its entirety is spent in the car, with Ivan, as he fields phone calls and attempts to put the pieces back together. We know nothing about him as the film begins, but each exchange gives us a new, critical piece of information, and gradually the picture begins to form.

Because of a mistake he made months ago, his marriage hangs by a thread, and he must abandon the pour — leaving it in the hands of a panicky Irishman (Andrew Scott, Sherlock) — to deal with the fallout. So over the course of a single lonely drive, he is constantly dialing, answering, steering into crisis after crisis, doggedly pursuing the noblest course even if (like Ned Stark) it means his own destruction.

The pleasures of Locke — though it is not “fun” in the traditional sense — come in the reveals, the trap doors that kick open and drop a new layer of resonance to Ivan’s increasingly-precarious position. In fact, I fear I’ve already said too much. I advise you not to read any more about the plot, anywhere. But it is enough to say that Hardy is effortlessly magnetic, even soulful; his monologues, when they come, are theatrically broad, and it’s weird at first, and then it isn’t. Because you’re hooked.

And the supporting players, who have only their voices to use, make exceptional partners for Hardy: Olivia Coleman (Broadchurch), Ruth Wilson (Anna Karenina), Ben Daniels, and Scott all succeed in creating three-dimensional characters despite never appearing on screen. As a chamber play, Locke is wildly successful. The internal logic, the conflicting motivations, are entirely sound. And there’s no cheap drama — no police stops or pedestrians, just to get another face on screen. It’s all Tom Hardy, and it works.

But it’s an extremely difficult thing to maintain the visual momentum of a film like this; you can only see so many headlight bokehs float across the screen, or so many cutaways to Ivan’s dashboard display. But there’s an impressive variety of angles, taking us all around and outside the car without the cinematography calling attention to itself, even if the editing occasionally leans toward the expressionistic. In truth, I’m not sure how Knight could have done it better. He made the smart choice: putting his trust in his words, and his cast, and his audience to not need an over-produced stylistic assault.

At the heart of Locke is an absorbing story about honor, families, and regret, one of an imperfect man attempting to navigate out of the rocks. But Ivan is never more alive than when talking about, of all things, concrete. The pouring of a foundation. Because at least until that happens, the finished skyscraper can still be as perfect as it exists in his mind. It’s the realities of the world that will always find a way to screw things up.

Grade: A-