Tilda Swinton and Michael Shannon Took Shelter

With “The Act of Killing,” director Joshua Oppenheimer approached the documentary form in a radical, seemingly unthinkable way, inviting his subjects — Indonesian gangsters who had once served on the country’s death squads — to reenact their crimes on camera. Why should his narrative debut be any more conventional?

For “The End,” Oppenheimer conceives a peculiar post-apocalyptic musical, confined to an underground bunker where an elite set of people have hoarded fine art and expensive wines for a cataclysm that, perversely enough, they may well have instigated. Oppenheimer got the idea from a documentary he was developing about a “very wealthy, very dangerous family” (in his words), but ultimately chose to steer the project in a very different direction.

With its turgid 148-minute running time and defiant lack of compelling conflict, “The End” doesn’t pander to mainstream sensibilities. Rather, Oppenheimer appeals to the art-house crowd with a serious-minded rumination on guilt and the human capacity to rationalize away one’s misdeeds. The filmmaker hatched the project before the COVID-19 pandemic, but somehow failed to consider that audiences have had their fill of claustrophobic shut-in stories.

The resulting fable surely would have benefited from some kind of suspense — say, a thriller element that threatens its tight group of survivors — but Oppenheimer stubbornly resists such concessions. In the end, “The End” is less a musical as we might imagine than a handsome highbrow drama interspersed with melancholy original songs (fewer than you might think), penned by Oppenheimer, then set to music by Joshua Schmidt (a theater composer making his big-screen debut).

The experience begins innocently enough, with a bright-eyed 20-year-old (George MacKay) who can’t recall life before lockdown, as he tinkers with an egregiously inaccurate diorama (he has Indians, settlers and slaves coexisting at the foot of the Hollywood sign) and sings sweetly to himself. He could be Ariel in Disney’s “The Little Mermaid,” puzzling over her whozits and whatzits galore, naively daydreaming of life on the surface. Like dawn breaking, “A Perfect Morning” makes for a lovely opening number, though MacKay’s voice, like those of the rest of the cast, doesn’t sound trained for singing. Perhaps Oppenheimer wanted it that way.

Identified simply as “Son,” the young man was born in this doomsday shelter and knows no other reality, though his parents have spent the past two decades repeating their self-serving version of events. Mother (Tilda Swinton) reminisces about her time with the Bolshoi, though it’s doubtful she ever performed. “We’ll never know if our industry contributed to rising temperatures,” says his energy-baron father (Michael Shannon), who’s clearly in denial about the world they left behind — a world they helped to destroy.

Down here, safe from whatever horrors befell humanity, the boy’s parents have maintained whatever sense of culture they can, with the help of a personal doctor (Lennie James), a butler (Tim McInnerny), a maid (Danielle Ryan) and an old friend (Bronagh Gallagher) from those earlier times. Mother spends her days rearranging the priceless artwork on the walls — including Renoir’s “The Dancer,” Monet’s “Woman With a Parasol” and awesome, enormous landscapes — and fussing over details like cracks in the plaster.

It’s been 20 years since they retreated to this self-sufficient bunker, and any notions of “normalcy” have long since been rendered irrelevant. They “religiously” observe all the holidays, putting on small, absurd pageants. Otherwise, “each day feels exactly like the last,” Swinton sings nearly two hours in, as part of her shattering (if shrill) “Dear Mom” solo. Their routines include swimming lessons and emergency drills, as survival is their priority — but to what purpose?

That seems to be the driving question of “The End,” which implies that people like these would have done better to prevent the apocalypse than to plan for it. For a time, the film plays like the extended womp-womp of a sad trombone at the end of a disaster movie, in which seven characters make it while the rest of the world perishes. Then what? Mother and Father raised the boy in their own image, making him the historian for their distorted truth while warning him of the danger of “strangers.”

And then one arrives, identified only as “Girl” (Moses Ingram). She expresses guilt for abandoning her family, which in turn dredges up long-suppressed emotions among the others, who made impossible sacrifices during the early days of the end. “Mom, in the beginning, did you see the people trying to get in?” her now-skeptical son asks. Such questions are not just inconvenient for the family, but also reflect the generational schism unfolding now in America, as young people judge find their parents’ actions tough to forgive.

Mother had no intention of letting this outsider in. “We have to draw the line somewhere,” she says. Long ago, they killed people for trying, and the butler bears the scars to show for it. But 20 years is a long time to go without news of the outside world, and the family warily allows the Girl into their bubble. Aside from MacKay, who brings a touching form of sweetness to the role, Ingram is the only member of the ensemble to display hope. The others all suggest the desiccated husks of humanity, keeping up appearances as best they can. Surely, whatever audiences experienced during the pandemic will inform how they process the intruder, though Oppenheimer approaches her with cautious optimism.

Together with “Melancholia” production designer Jette Lehmann, Oppenheimer presents an elegantly drab bunker, buried deep in a salt mine but built for comfort — not unlike the Elon Musk-inspired base seen in last year’s “A Murder at the End of the World,” a project that delivers its big-brain ideas through effective genre devices. Oppenheimer would have done well to take a similar approach, though his resistance to such choices earns “The End” the imprimatur of capital-A art (at the expense of capital-ist entertainment).

Who will see “The End”? Premiering at the Telluride Film Festival, it feels destined to flop, while also being championed by those critics and audiences who rightly feel that such risks are to be encouraged. Oppenheimer’s audacity (and that of his backers) is to be commended, though his portrait of a certain highly idiosyncratic form of foolishness can’t help feeling foolish itself. Before any musical finds its way to Broadway, it is workshopped and tested to within an inch of its life. This one seems to have breezed past such steps, trusting the vision of its maker over the needs of its audience.

There may never be another film like “The End,” and that alone makes it special, though surely all involved would prefer for it to be seen. As it is, the film feels like an obtuse missive, hidden in plain sight, just waiting for intrepid seekers to unearth it.