Hannah Arrendt’s famous phrase “The Banality of Evil,” gets beaten to death by anyone trying to describe the ordinary folk who commit extraordinary crimes, be they fictional villains or political, military or historically genocidal figures who shock the world both with their psychopathy and their everyday, “quiet next door neighbor” dullness.

But it’s best applied as she intended, to the monsters who perpetrated the Holocaust. That routine heartlessness, cruelty and widespread complicity is at the heart of Jonathan Glazer’s quietly horrific “The Zone of Interest.”

Very loosely based on the Martin Amis novel, which fictionalized the family life and sexual shenanigans of the commandant of Aushwitz, “Zone” is a cryptic, underexplained tale that buries us in banality and educates us about evil.

Simply put, we see a company man — SS camp commandant Rudolf Höss (Christian Friedel) try to come off as a casual careerist, hobnobbing with industrialists looking to improve their profits in the “manufacturing” side of the vast German concentration camp, looking for efficiencies from contractors who have designed a quicker, faster, mass-extermination-ready crematorium, pocketing stolen loot from the Gypsies, Slavs, homosexuals and Jews and enjoying the comforts of slave labor, not just for the camp, but for keeping his comfortable home just outside the gates.

I kept thinking of the late Tom Wolfe”s lampoon of Southern affluence and gentility, “A Man in Full,” as Höss dons his boots and mounts his horse to ride through the “Arbeit macht frei” gate to work each day, as he took a smoke while removing the boots for an Auschwitz inmate to clean and polish or blithley wanders the large, immaculate garden that another inmate was responsible for keeping.

Sandra Hüller of “Toni Erdmann” and the recent “Anatomy of a Fall” is Hedwig, the matriarch of the household, mother of five Höss children, who jokes to her visiting mother that the officers’ wives and perhaps even the inmates, refer to her as “The Queen of Auschwitz (in German with English subtitles).”

She may be the most monstrous figure here. The British director of “Sexy Beast” and “Under the Skin” makes Hedwig EveryGerman who “doesn’t want to know,” but we know does. She parcels out confiscated clothing, tries on a stolen fur coat, and when a young servant is clumsy, inattentive or otherwise provocative, Hedwig lets drop that she could have “your ashes” scattered over the fields and forest surrounding the death camp that sits on the other side of that wall topped with barbed wire.

She knows exactly what’s happening, and what her entire lifestyle is built on.

One chilling moment has their Hitler youth tween son sorting “teeth” with gold fillings at bedtime, something he admits to when his much younger brother wants to know what he’s doing under the covers.

The film opens with a blank screen and the sounds of the camp captured in the distance — manual labor, shouts and occasional muffled screams, distant gunshots. This echoes throughout “The Zone of Interest,” with every walk through the garden, every open window in the house underscored with what goes on under the smoke we see billow from chimneys from the heart of the death factory.

The sounds, when we notice them, are disturbing. When we stop noticing them, as the Höss family do, that’s even more disturbing.

This Polish co-production was shot in and around the real Auschwitz, and lets us glimpse the historic site as it is today — vast exhibits of the luggage and shoes and uniforms of those who didn’t survive Germany’s mass extermination.

Glazer’s most artistic touches are showing a young woman sneaking around the edges of the camp after dark, picking apples off fruit-filled trees, hiding them on outside-the-gates work sites so that the starving people inside can find them as they dig or load coal. These sequences are filmed in stark black and white night negative footage.

But it is the brittle, inhuman discussions of efficiency in a radial-shaped new crematoria, the political scheming, the corruption of an ordinary man who sorts out stolen currency on his desk and uses connecting tunnels in the complex to have assignations with inmate sex workers, that gnaws at you.

Friedel (“13 Minutes”) gets across the monstrous contradictions of Höss, never letting us see a lip-smacking sadist, virulent anti-Semite or simple “monster.” He takes a couple of kids kayaking so that they can swim. And he’s revolted and panic-stricken when he steps on a human bone in the river flyfishing. He kisses his horse goodbye when he is transferred, and dotes on his children on picnics.

And then the jackboots go on and we’re reminded of why he has that severe SS (shaved all around) haircut. He’s all business, and his business is mass murder.

“The Zone of Interest” can be tedious in its depiction of banality. Never seeing inside the camp, with the many trains rolling in only depicted as smoke puffing up over the forest, mutes the impact of it all. The action has a flat quality, as the violence is always out of sight and muffled, even when we hear it. But there’s no denying that it’s there. The evidence is oblique but damning. Hedwig’s mother can sense it, perhaps smell it, when she visits and then flees.

Glazer’s film has a timely quality, with nationalism, fascism, anti-Semitism and “ethnic-cleansing” going on all around us. It’s a reminder that justice didn’t come to all, that the most extreme “punish the Germans for their collective sins” advocates were drowned-out by the exigencies of the “next war,” the Cold one.

Not all history is triumphant, and perhaps the ugliness is the most important part of the past to remember, to teach and learn from. The banal of today have to see what the banal of the past perpetrated, tolerated and were lessened by and stained with for all time so that “never again” won’t happen again, and that we sound the alarm when it does.

Rating: PG-13 for thematic material, some suggestive material and smoking.

Cast: Sandra Hüller and Christian Friedel

Credits: Scripted and directed by Jonathan Glazer, based on the novel by Martin Amis. An A24 release.

Running time: 1:44