“My Name is Sara” is billed as biographical drama, and it is. The movie is based on the true story of Sara Góralnik, who escaped Nazi persecution in Poland, adopted the identity of a Christian classmate, and worked as a nanny on a Ukranian farm throughout the War, and it’s produced in association with the Shoah foundation and executive produced by her eldest son, Mickey Shapiro. But its cumulative impact is that of a thriller, and its most effective scenes are almost unbearably uncomfortable, as they revolve around a character who is escaping genocide by pretending to be something she isn’t, and could be murdered if the truth gets out. As directed by Steven Oritt and written by David Himmelstein (screenwriter of many acclaimed historical dramas, including “Soul of the Game”) the movie excels at putting the audience in the position of its 13-year old heroine (Zuzanna Surowy), who’s lost and alone in hostile terrain, making things up as she goes, and doing whatever is necessary to live one more day. The story begins with Sara and her elder brother parting ways after he tells her that she has a better chance of getting through the war because he’s more identifiably Jewish than she is. His insight is only partially borne out: from the moment that Sara gets work as a nanny on a farm in the Ukraine (which is also under German control) barely a scene passes without somebody either casting doubt on her story or looking at her in a way that makes us think she’s being suspected of lying. Sara tells the farmer, Pavlo (Eryk Lubos), and his wife, Nadya (Michalina Olszanska), that she’s fleeing a bad domestic situation—that her mother died, her father remarried with a woman who hates her and had a new baby with her. Although Pavlo accepts this story, Nadya doesn’t buy a word of it. For much of the rest of the film, she stares daggers through the heroine no matter what’s transpiring. Drawing on the real Sara’s story, the movie contrives situations where Sara could be found out unless she manifests instincts or generates knowledge that will permit her to “pass” (such as being able to make the sign of the cross, some she learned from her Christian friends). So deft is the film’s mastery of simple subjective filmmaking techniques that when Sara enters a small-town church, it’s as if we’re following a mouse into a barn filled with cats. Sometimes the movie turns the thumbscrews on the audience by letting us know that an uncomfortable moment is coming long before it happens, as when Sara tells a woman during a trip to the local village that she hails from a particular city, and the woman says she can’t wait to see her again next week so that she can connect her with somebody who’s known her since she was a little girl. The film also excels at showing how small-minded and thuggish occupying armies tend to be. The Nazis soldiers that cross paths with Sara and her employers and their two young boys are bullies in uniforms, craven and vicious and often borderline incompetent except when it comes to brutalizing unarmed people. The Russian partisans who show up midway through the film demanding meat from the family farm are only marginally better: it seems clear from how eagerly they beat up Pavlo and grope Nadya and mock the boys for crying that the political righteousness they cite as justification for their actions is merely a cover for their thuggish nature. If there wasn’t a war going on, they’d probably be bandits robbing travelers on the road. This is also a refreshingly nonjudgmental film. Everyone in it seems to be doing the best they can to muddle through a rotten situation that they didn’t create and are largely powerless to control (though the ones with guns and uniforms get to take refuge in vicious power fantasies). But the film doesn’t excuse anyone, either. Sara constantly struggles to behave morally and ethically in an environment where people who put those concerns at the forefront of their minds tend to end up in prison or on the wrong end of a rifle. The film doesn’t so much end as stop, like all ordeals. It’s torment in cinematic form, made comprehensible and engrossing by its focus on a singular experience, and the performance that anchors it. Zuzanna Surowy has never acted in a film before, but she seems as if she’s got years of experience. She has that gift of letting the surroundings and events absorb and reflect her. We really do feel as if we’re seeing it all through her eyes, including the very worst of it.