"Brick Lane" opens in Bangladesh, where two sisters play happily despite the poverty of their village. Then their mother dies, and suddenly life changes for the older sister Nazneem.
"I always said, 'I will not marry and be sent far away,' but our father chose me an educated man, living abroad. My sister would stay. I would go. If Allah wanted us to ask questions, he would have made us men," Nazneem says in the film.
Nazneem leaves her village in Bangladesh at age 17 to live in the dismal streets of the Brick Lane area of London with her new husband, Chanu.
He is 25 years her senior.
The story picks up more than a decade later when she has two teenage daughters of her own, and tensions in the Muslim community are mounting as a result of the 9/11 attacks.
"Brick Lane" director Sarah Gavron worked on making the film for three years. Part of the challenge, she says, was taking Monica Ali's multi-layered novel and paring it back.
"We almost could have done the parallel story of two sisters, but we decided to focus on Nazneem as our protagonist and center it on the year of 2001, when really she falls in love and she changes," said Gavron.
"Brick Lane" follows Nazneem as she begins to chafe in her loveless marriage. She writes longingly to her sister about her desire to return to Bangladesh.
Then she falls for Karim, a man closer to her own age, who urges her to leave her husband. When her husband announces he is taking the family back to Bangladesh, Nazneem is left with a terrible choice.
Gavron says she and her cast took the unusual step of consulting the novel regularly, then using what they gleaned as the basis for improvisation.
"From my point of view, I liked leaving a lot open," Gavron said. "We had the book as our source and we had a very solid script. Nevertheless, there were moments that changed as we went along."
Gavron says one of the main reasons she was able to take this approach was because of the talents of Tannishtha Chatterjee, who plays Nazneem.
Chatterjee says the role was challenging. Nazneem rarely speaks, particularly early in the film. Chatterjee had to find ways of expressing the nuances of her characters transformation.
"From a shy 17-year-old introvert girl when she came to London for the first time in an arranged marriage situation, married to a man 25 years older to her, and finally she finds her own voice in her own way," Chatterjee said.
Having made films in her homeland of India and in Europe, Chatterjee says she was attracted to "Brick Lane" because, she says, unlike many South Asian stories, there are no easy answers.
"There are all these black and whites and good and bads, and that wasn't the story," Chatterjee said. "It's really a complex story of human relationships."
As time passes, Nazneem sees new qualities in both her husband and her lover, making her decision to stay or leave ever more difficult.
It's a story of knowing where to call home. The film has already been released in the UK, and some European and Asian countries. Director Sarah Gavron says she's been pleased by how it has resonated with audiences in very different places.
"Whether they were people who had moved just from different parts of Britain, or someone who had had an experience of their daughters feeling displaced," Gavron said. "Or just the love story resonated, or that feeling of being in a marriage that wasn't working."
Both Gavron and Chatterjee say they have been approached by women far from the Bangladeshi community in London, who have said their film tells the story of their lives.
"Brick Lane" is the latest film to come out of Britain's South Asian community. Sarah Gavron hopes it will enjoy similar success to "Bend it Like Beckham" and "East is East."
"I think it's where the most interesting stories are at the moment, in immigrant communities. And the Asian community have just been there long enough now for the next generation to be telling those stories," said Gavron. "They deal with culture clashes and generational conflict, and there's just so much material to be explored."
Gavron says she expects the novels and the films to just keep coming out of the South Asian community.