Filmmaker Arnon Goldfinger is currently in Berlin for yet another opening of his film, “The Flat,” the fascinating and award-winning documentary on the discoveries he makes about his maternal grandparents while cleaning out their Tel Aviv apartment.

But despite the string of festivals attended and prizes won by Goldfinger in the last year for this riveting film, he’s excitedly apprehensive about the launch in Germany. Given his grandparents’ complicated ties to their native country, which they left before World War II and which they replicated in their Tel Aviv home, Berlin and Germany weigh heavily in the film.

“It’s very emotional and exciting for me,” he said, anticipating the film’s release in 25 German theaters. “It’s for sure a movie that will speak to the German audience, and their reaction will be interesting.”

When the film was in its final stages of editing in Berlin, where part of it was filmed, Goldfinger insisted on a last screening to ensure that “every word was clear.” With several languages spoken in the film, including German and Hebrew, he invited both Germans and Israelis, from among the many ex-pats currently living in Berlin, to the screening. While the reason for the screening was technical in nature, no one remembered that fact by the end of the film, when they were caught up in Goldfinger’s story.

The film tracks emotional revelations and relationships as Goldfinger and his family clean out the apartment they teasingly referred to as “Berlin in Tel Aviv.” Over the course of the project, he finds documents that point to his grandparents’ relationship with a pro-Zionist Nazi, both before and after the war, in Palestine. He tracks down the German descendants of his grandparents’ friend, and throughout his investigation, discovers information that affects his own familial relationships.

One of the women at the initial Berlin screening, an Israeli who has been living in Berlin for many years, told Goldfinger that she identified with several characters in the movie who didn’t know or didn’t want to know about the their family’s Nazi connections and Holocaust history. She confided to him that she didn’t want to research her German husband’s grandfather’s connections before they got married, because she would rather avoid knowing about any Nazi history.

For Goldfinger, who made the film over the course of five years, the depth of viewers’ reactions to the film was surprising.

“The first and strongest reaction was that other people also had that kind of story,” he said. “It made sense, but it was surprising.”

He’s heard from several viewers who first saw it themselves and then brought their parents, siblings and children to see it another two or three times. Other viewers said they saw it and then went home to clean out their own closets, having learned not to assume that all questions can be answered when the relevant people aren’t around to answer any longer.

“It doesn’t matter what you do or think or say — everyone has an interest in their past,” surmised Goldfinger. “You can’t not. But some people never get around to it, and this film makes you start to think about that.”