“The meaningful things are left unspoken,” Arnon Goldfinger says at the start of his documentary film The Flat. He doesn’t seem to have known this when he went with his mother to his grandmother’s apartment in Tel Aviv after she died. What he found among the art, furnishings, and memorabilia was a lot more than he expected. He found a strange, suppressed personal history that altered his family’s understanding of itself, and maybe the world.

The grandmother lived in Israel for 70 years, without ever learning Hebrew, after she and her husband Kurt fled Nazi Germany in 1936. But, it transpired, she and his grandfather had toured Palestine with an aristocratic senior Nazi three years earlier, and after the war, this Jewish couple reestablished their friendship with this man. This, in spite of his association with one of the organizers of the Holocaust, Adolf Eichman.

How this all could have happened becomes the object of Goldfinger’s quest, and the subject of his documentary. His movie patiently follows him around Israel and on to Germany as he searches for answers, eventually in the company of his semi-reluctant mother, who seems sometimes to want to let this queer and disturbing past rest undisturbed.

The Flat is low-key but has an intriguing problem at its core. It, and Goldfinger, never quite resolve these questions, and the director-sleuth seems to miss the opportunity to contextualize the situation on a larger social and historical scale. But the lingering questions nag and resonate, anyway.

Watch the trailer for The Flat