PASSAU, GERMANY -- The Nasty Girl wears bunny slippers, has a head full of frosted curls and giggles like a school kid.

Anna Rosmus doesn't look like a nosy, know-it-all Nazi hunter. It's hard to imagine her mother-in-law saying that because of people like Rosmus, Germany needs another Hitler. Hard to imagine the mayor, the priests and many of her family's friends deciding that Rosmus is so evil that she deserves to be "gassed, chopped up and pulverized," as some of Passau's leading citizens said.

Rosmus is a 30-year-old graduate student and the inspiration for German director Michael Verhoeven's "The Nasty Girl," which opens today in Washington. The film, the story of Rosmus's decade-long battle with her hometown during the late '70s and through most of the 1980s, is much like Rosmus -- determined, cheeky, charming and even funny.

It is a story about the power of history, about the confrontation between a town that decided to forget and a young student who wouldn't let it.

Passau, deep in Bavaria, is, as Verhoeven says, "just another German town." Its medieval city center has been restored to fantasyland colors. Its new downtown boasts a chrome and glass indoor mall, the pride of the city fathers.

Passau also has more than its share of secrets. The house where Hitler lived as a child became a museum to the Fuehrer during the Third Reich. The American occupation forces closed the museum in 1945 and gave the house to the Passau Jewish community. Now the building is a private house and, oddly enough, no one seems to know where it is. Ask passersby, the tourist information office, even the mayor's office, and they're not quite sure where it is. Perhaps you'd like to see the lovely cathedral instead?

Rosmus was still in high school when her favorite teacher suggested she enter an essay contest that could win her a trip to Paris. She wrote about "Freedom in Europe." Nice milquetoast topic. No one was offended. When little Anna won the top prize, the whole town cheered her on. There were ceremonies at City Hall, parties, a proud feeling all around.

The next contest beckoned. This time, Rosmus decided to write about "My Hometown in the Third Reich." Yes, well. It's good to show interest in history, the town librarians and teachers told Anna. Surely you'll want to write about Passau's resistance movement against the Nazis.

Rosmus wasn't quite sure exactly what she wanted to write about. She isn't Jewish, but she was curious about her town's treatment of Jews. Mostly, she wanted to see the old newspapers and other archives tucked away in a locked cabinet in the city library.

The city refused her access. It would come to regret that move.

Rosmus began a four-year legal effort to pry the records out of the hands of city officials who, it turned out, had pretty good reasons to resist her research. As Rosmus pushed harder and harder, learning to enlist the aid of out-of-town newspaper reporters, the town turned against its child with a venom that betrayed Passau's placid storybook facade.

"The Nasty Girl" portrays Anna, renamed Sonja Rosenberger in the movie, as an innocent, inquisitive waif who likes to yodel in the woods and has a crush on her dangerously dark teacher from the big city. Rosmus is unremittingly cheerful, and she did indeed marry her teacher (who then left her when the going got tough).

The film is "so real I'm afraid of it," Rosmus says. She has seen it more than half a dozen times.

Rosmus is, however, no innocent. She cherishes every victory over the mayor and the locally prominent men she unmasked as ex-Nazis, or Nazi sympathizers. Her awards fill the walls of the house she shares with her two young children. She still sends alerts to reporters around the world when she discovers a new antisemitic outrage. She stands ever ready to pull out the evidence that proves that a Passau clergyman once denounced a local Jewish businessman, sentencing him to death at the hands of the Nazis.

"Was she so curious?" asks Verhoeven, who won best director prize for "Nasty Girl" at this year's Berlin Film Festival. "Or did she think, 'They don't want me to have the information, so I want it even more.' She was stubborn."

Anna refused to let memories fade. She discovered that there had been concentration camps right in her own town, that everyone, even her own grandmother, knew where they were, but simply chose to be silent.

In the film, Sonja's house is bombed, her cat nailed to a wall, her children taunted and threatened. Not true to life, but acceptably close. Rosmus was not bombed, but she did receive anonymous bomb and murder threats. Once, neo-Nazis recognized her in a Munich restaurant and pummeled her into unconsciousness.

Police once caught a man with a butcher's knife running toward the tent where she and her family were camping on vacation. She was spat upon by strangers and acquaintances on the streets of Passau. People did indeed walk up to her and ask, "Are you working for Wiesenthal?," the Austrian Jewish Nazi hunter.

Rosmus discovered that the brother of the local newspaper's editor had been a Nazi sympathizer. The editor responded by banning Rosmus's name from the paper; for five years, during which the student battled every level of city bureaucracy, the Passauer Neue Presse published not one word about the controversy.

"It was really just a little girl writing a school report," says Hermann Schmidt, cultural editor of the Neue Presse, which, now under new management, no longer bans Rosmus from its pages. "What she did was fine, but I don't like the way she did it, seeking publicity, beating a good thing to death."

The escalation of Rosmus's dispute with virtually all of Passau was not only her doing, Schmidt concedes. The town, he said, contributed to it.

"Passau is like every other German town. There were Nazi swine everywhere and they are still alive." When Rosmus started getting uppity, he said, "people smelled blood" and went after her. "They created a martyr."

On the narrow medieval streets of the charming Bavarian town where Adolf Hitler spent his youth, where Adolf Eichmann was married, the name of Anna Rosmus still raises ire.

"The Nazi time is over and you should forget about it," says Hermann Haydn, a student who recently completed military service. "If you think about it always, you get very depressed and that's no way to live. Anna Rosmus overdoes it."

"Those were hard times for the older people and they shouldn't be forced to live it again," says stock clerk Franz Heidner, 36. "Times have changed. This stuff is always coming up, stories about the Nazis and concentration camps. They should just leave it alone. You should remember, but not always."

When "The Nasty Girl" opened here this spring, the town fathers were invited to the opening. Few showed up. The vice mayor, Fritz Abelein, went, sank deep into his chair and at the end of the screening ran to the rear exit of the theater to escape the inquiring press.

There was even talk of banning the film, but after years of bad publicity, the authorities were wise enough not to present Rosmus with another such lovely gift. Instead, they declared obscene and banned the movie's poster, which depicted a bronzed statuette of a nude woman. (Rosmus was ready for that move; in her typically cheeky manner, she offered to pay for Pampers so the city could cover up the hundreds of nude angels in the Passau cathedral.)

H.P. Heller, a town councilman who has no plans to see the film, says Passau handled the Rosmus affair poorly. "They should have cooperated with her, such a nice, blond little girl. The general opinion here is that we have no connection to those times. It's not interesting anymore."

Verhoeven says he was at first astonished by the vehemence of the reaction against Rosmus because her research uncovered relatively minor misdeeds: prominent townspeople who wrote articles in favor of the Nazis or who made antisemitic statements. "These were not mass killers she was investigating," Verhoeven says. "This was only daily life."

But the director came to realize that Rosmus's small revelations were powerfully significant in a small town. She discovered in the city archives that the editor of the local Catholic newspaper, who had passed himself off as a resistance member, had actually written pro-Nazi articles in which he urged Passauers to pray for Adolf Hitler, a good man.

The Catholic editor sued Rosmus for slander and invasion of privacy. He wanted $300,000. When the case went to trial, the judge told Rosmus that he would dismiss the case if she signed a declaration stating that the editor was not a committed Nazi, that he did not want to murder Jews, that he only expressed antisemitic beliefs.

"Okay, he wasn't really a strong Nazi," Rosmus says. "So I was willing to say that, but I must also have the right to say that he was no resistance fighter either." She refused to sign the declaration.

Instead, Rosmus, by then a pro at using the press, invited British, Swedish and Israeli reporters to attend her trial. "At that moment, it was declared that the trial could not go on because the judge had fallen out of an apple tree," Rosmus says. She laughs, relishing the moment even now, years later. "I didn't have to pay anything or make any declaration."

Ten Passauers have taken Rosmus to court. None has won anything.

Rosmus chooses to remain in Passau, where she is working on her doctoral dissertation and second book, a study of Jewish life in Passau before the concentration camps. She has few friends in town. Even her supporters are tired of her continuing battles against the Passau establishment.

Nonetheless, she stays and, even now, battles on. While working on her doctorate, she placed advertisements in New York German-Jewish publications, looking for refugees from Passau who could give her information about their shattered community.

"More and more, the replies gave me the feeling that these people were homesick, that they were Passauers," Rosmus says. She went to city hall and visited her old nemesis, the mayor. She wanted him to invite the city's former Jewish citizens to return for a visit, at Passau's expense.

"The mayor told me, 'I didn't send them away, so I won't invite them,' " Rosmus recalls.

So Rosmus went right ahead and sent an invitation to New York painter Robert Klein, inviting him back to Passau on behalf of the city. Then, after Klein accepted, Rosmus returned to city hall, this time with a friend who posed as a reporter, microphone and all.

Suddenly the mayor decided to invite Klein to give an art exhibition in Passau.

Some weeks later, when Klein was about to arrive, Rosmus went once more to the mayor. She wanted an official city welcome for Klein at the train station. The mayor refused.

On the day before Klein was to arrive, Rosmus called the local newspaper and informed editors that the mayor would be at the station to receive the returning Passauer. The paper printed the information.

"The next day," Rosmus says, "I was at the station with my daughter, a rose, a sign saying 'Shalom,' 200 people who wanted to see a real Jew -- and the mayor. Mr. Klein wrote me later saying what a great feeling it was, especially to be received by the mayor."

Rosmus sits silently smiling, basking in the brilliance of her own tactics.

Verhoeven, who made a documentary about Rosmus for German television before he completed the feature film, says he quickly discovered her talent for getting what she wants in a city whose leaders despise her.

"For me, it was very difficult to get cooperation," the director says. "But they know it is much more dangerous to oppose Anna because the newspapermen from all of Germany will be there immediately to write about it. Still, that doesn't mean they want to help Anna. They are offended by her, and by me."

Rosmus says she is interested in far more than rattling the memories of elderly townspeople. "This film, the research I have done, it all breaks a taboo," she says. "You can only change what happens now or in the future if you understand what happened here. We couldn't prevent Nazism, maybe we can't prevent the next war. All we can do is make people more sensitive."

Rosmus is fearful of the reunited Germany, worried by the persistent parades of neo-Nazis and other nationalists in the eastern part of the country.

"Germans are proud to be big again," Rosmus says. "In East Germany, especially, the feelings against foreigners and the Jews are coming out after all those years of suppression. And here in the west, we don't have our main enemy anymore, so many Germans are searching for a new enemy, maybe the Turks."

So she returns to the libraries, searching for a past even her friends prefer in small doses. "I'm not proud to be one of the few," Rosmus says. "I'd rather be the normal case."