The memories are visceral, a sharp poke in the gut: shattered windows and the mournful crunching of glass underfoot; the sadness of the Torah poking through mounds of ashes; the menace of marching black boots; the terror of a doorbell ringing in the dead of night.

In Germany, Hitler rises, and life is irrevocably altered. There is the humiliation of a young boy who discovers that the neighborhood ice cream parlor is suddenly off limits, thanks to a sign that reads, "No dogs or Jews." The horror of Kristallnacht, when Germans ransacked Jewish homes and businesses. The grief of families ripped apart and shipped off to concentration camps, many never to be seen or heard from again.

This is familiar terrain, tragic territory that's been mined again and again. But "Shanghai Ghetto," a documentary that opened this week in Washington, goes on to follow Jewish refugees as they find an unexpected refuge: China.

Beginning in the late '30s, about 20,000 Jews settled in the sprawling port city, which was at once "tremendously wealthy and miserably squalid." Shanghai was an international enclave, a haven for foreigners, because "Western law ruled" -- at least until the city came under the grip of Japan.

In Germany, one survivor recalls, the U.S. Embassy shut its doors, offering no assistance to frightened Jews. Quite simply, there were no passports or visas to be had. But there was one place, "8,000 miles away," where you didn't need paper to enter. The conditions were quite often squalid, and occasionally horrific. A bucket served as the bathroom. Children held competitions to see who could pick the most bugs from their rice. Tiny wrapped bundles waited in the streets, garbage to be carted off: the frozen corpses of Chinese street kids who'd died in the bitter cold. And there were all kinds of diseases waiting to claim new victims: chronic dysentery, parasites, polio. Later, when the U.S. bombs came, raining down on Shanghai in an effort to flush out the Japanese, dozens of the refugees perished.

But as the Jewish survivors of Shanghai came to realize, compared with their relatives left behind in war-ravaged Europe, they were living in "paradise." They created their own lives there, building Jewish theaters, opening delicatessens, starting newspapers and boxing clubs, struggling to keep something alive amid the numbing poverty and isolation.

"Shanghai Ghetto," narrated by actor Martin Landau, is told from the perspective of five survivors (one is the father of one of the documentarians), with three academics adding historical context. The filmmakers, Dana Janklowicz-Mann and Amir Mann, slipped into China with the former refugees, shooting with a digital camera. In the opening segment, black-and-white still shots of Shanghai circa 1939 flit across the screen, seamlessly morphing into live footage of modern-day Shanghai, a technique that is repeated when two of the survivors return to the homes where they lived as children.

As documentaries go, "Shanghai Ghetto" isn't taking any creative risks. At times it plods along, offering merely a serviceable treatment of a little-known subject. Part of the problem is the narrative technique: traditional shots of talking heads interspersed with archival footage. There is little to indicate what the lives of the survivors are like now, how they got from there to here -- wherever "here" is, as they scattered to other lands, including Israel and the United States, after the war.

Also, there is little mention of the interaction between the Chinese and the Jewish refugees, beyond that the Jews quickly sussed out the situation and realized that the Chinese were even worse off. (The Japanese soldiers are remembered as tyrants whose whims made the difference between a miserable existence and a barely tolerable one.)

The two oppressed groups, Jews and Chinese, forged a mutual tolerance that progressed no further. The children played together, one survivor observes, but there were "no lifelong friendships." Considering that the Jewish refugees were in Shanghai for 10 years, that's pretty damning testimony, speaking volumes about racial differences and the way that refugees of one land cleave together to the exclusion of all else.

As one survivor puts it: "If my grandchildren don't grow up Jewish, Hitler won the war. . . . Anti-Semitism never bothered me as much as assimilation." Too bad the filmmakers don't pursue this further.

Indeed, what's missing is a more nuanced contextualizing, some mention of how class and cultural differences among the different Jewish groups played out. At the top of the pecking order were the wealthy Baghdad Jews and the slightly less affluent Russians, both groups established for years in Shanghai. Lower down was the later class of refugees, who ranged from the German bourgeoisie, standing in the soup lines decked out in their business best, to the "religious Jews" who kept kosher and insisted on being treated differently from the other refugees.

Despite the film's shortcomings, the stories are quietly moving. Telling of relatives lost and parents who died too young in their adopted land, the survivors stop, tears choking the words.

"It all comes back," Betty Grebenschikoff murmurs as she picks her way through the one room that served as her family's Shanghai home. "It all comes back." In that moment, decades of memory and pain are felt, and the viewer can't help but feel it, too. And that is the essence of good storytelling.

Shanghai Ghetto (95 minutes, at Visions Cinema/Bistro/Lounge) is not rated but includes images of Nazi atrocities and emotionally distressing anecdotes.