A quietly brilliant study in cognitive dissonance, "The Flat" is a documentary look at Holocaust denial, but not the kind you might think.

It begins, blandly enough, as Israeli filmmaker Arnon Goldfinger is clearing out the Tel Aviv apartment of his 98-year-old grandmother, a Jewish immigrant from Berlin who has just died, leaving behind boxes containing a lifetime of newspapers, letters, photographs and other ephemera.

As he and his family sift through the material, the documents reveal a story that forms the spine – and the spine-tingling mystery – at the heart of the film. What Goldfinger first discovers is only the tip of the iceberg: an unexpected friendship between his grandparents, who left Germany just before the war, and a Nazi SS officer by the name of Leopold von Mildenstein.

It's bizarre enough that Kurt and Gerda Tuchler, Goldfinger's maternal grandparents, could have been pals with the man who hired Adolf Eichmann, the monster in charge of administering Hitler's "Final Solution."

But it's downright incomprehensible that the couple maintained the friendship not just through the war but beyond, continuing to visit von Mildenstein and his family in Germany well after 1945. It's especially incomprehensible considering a further piece of shocking evidence of the way in which the Holocaust touched the Tuchlers' lives.

It's a piece of evidence that none of the Tuchlers' surviving relatives knew about and that Goldfinger's grandparents never spoke of. It's also a piece of evidence that von Mildenstein's daughter Edda (whom the filmmaker tracks down for some of the most uncomfortable interviews in "The Flat") didn't know about, or is in deep denial about, even after Goldfinger presents her with proof of her father's wartime activities.

What the evidence reveals is the way in which people psychologically compartmentalize evil – not just the evildoers and those who have evil done to them, but their family members, as well. In Goldfinger's meticulous, incremental presentation of the facts, which he lays out with the anguish of a crime victim, tempered by the masterful storytelling of a prosecuting attorney, the steady illumination of our minds' dark corners becomes subtly devastating.

How could a couple touched by the Holocaust fraternize with one of its apparent architects? And how could that architect continue to look into the eyes of those who had been persecuted as a result of his policies (or at least policies he tacitly acquiesced to)?

Then there's the generational ripple effect. Edda isn't the only one who seems willfully blind. Goldfinger's mother, Hannah, the Tuchlers' daughter, seems weirdly unmoved by the film's increasingly disturbing revelations.

Or maybe it's not so weird after all.

As Goldfinger's film suggests, perhaps we can't help but wall off the horrors we enact and those that are enacted upon us. Maybe we have to lock them away in the vault, along with the rest of our forgotten pain, in order to avoid going slowly, inexorably mad.

THE FLAT

★ ★ ★

Documentary in English, Hebrew and German, with English subtitles

Director: Arnon Goldfinger

97 minutes

Not rated (Contains disturbing thematic material)

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