“To me it wasn’t about a sexual awakening,” said Sarah Gavron, the director of “Brick Lane,” during a recent Dallas interview about her film based on Monica Ali’s best-selling novel, “so much as about an awakening.”

The plot centers on Nazneen (played by Indian star Tannishtha Chatterjee), a Bangladeshi woman sent to England seventeen years earlier for an arranged marriage with a much older, struggling businessman named Chanu (Satish Kaushik), with whom she has two daughters. Nazneen remains highly traditional in dress and manners even after so long a time in Britain. But when her husband loses his job she begins sewing in their small apartment to help the family finances, the work brings her into contact with Karim (Christopher Simpson), an English-born young man of Bangladeshi blood with whom she has an affair. After 9/11, however, Karim is radicalized, and Chanu decides to take the family back to Bangladesh, which Nazneen has idealized in her memory and the long correspondence with sister she left behind. But she must decide where her responsibilities lie, especially for her daughters; and she’s surprised when Chanu proves to have unexpected strength of character himself.

“The affair was just a catalyst,” Gavron explained. “It could have been something else. But it came along and opened her eyes to the world around her. She stops living in the dream world…and takes control of her own life.” And her attitude about her husband changes in the process. “You see that Chanu is this didactic, sort of odious buffoon,” she said. “But she realizes he’s wise and compassionate.”

Chatterjee expanded on Gavron’s point: “In many ways the relationship with Karim is the teenage infatuation which she never had. The only man she ever knew was her husband. And the only other man she ever knew after that was Karim. It was a catalyst, in a way. Ultimately she finds her own voice, and she does what she wants. But in doing that she’s not renouncing [traditional] practices.”

“That was one of the things that drew us [to it],” Gavron added. “The notion of two kinds of love [and] that it wasn’t offering easy answers on arranged marriage, and it didn’t judge those things but presented a marriage that was rather complex, where she did finally grow to love her husband. It was one of the draws for me, and, I think, one of the reasons that the story translates across cultures and generations and people just connect with it.”

The film is the first feature film by Gavron, who’d previously worked in television. “To me it was daunting,” she said. “Everything about it was a huge challenge.” But, she noted, the challenge began with the difficulty of transforming the book, which not only covers twenty years but consists largely of internal thoughts, often in the form of letters exchanged between Nazneen and her sister. She spent a full year working with the screenwriter.

“The book is five hundred pages and spans three decades, so the process of distilling it was about making tough choices,” Gavron said. “We went through many, many drafts. You could have told the parallel stories of the two sisters from the novel. Or you could have done a three-part life story. But we decided to focus on 2001, which is in the book, but to see it through the prism of just that year, and tell the other stuff as back-story.

“Our philosophy was to capture its spirit, the essence of it. A book is a book and a film is a film. You have to do what works, and we did make a lot of tough choices. But I hope what we’re left with is true to it. And when we showed it to Abi Morgan, the author, at a rough-cut stage, she thought that we had captured the spirit. That was reassuring.”

The internal quality of the writing was another challenge: much of the book is made up of Nazneen’s thoughts. “In a book you can do that beautifully with words,” Chatterjee said, “but how do you transform that in cinema?” Gavron noted, “One way that we thought to avoid [narration], apart from Tannishtha’s performance, was to make the camera subjective, so that everything about the movie—the sets, the sound, the lighting—reflect her emotional state. We tried to tell the story through that.”

Still, the approach left a great deal of the work with the actress.

“I have nothing else but my eyes, because Nazneen’s not a person of many words,” Chatterjee said. “She’s not a character of outgoing expression—it’s all inside her, all the time. Her world is so internalized, even in the letters where she does express herself sometimes to her sister. But then she falls in love and she wants to write to her, but she’s unable to.

“Actually if you see the whole journey that Nazneen goes through, there’s a definite beginning, middle and end, but without expressing herself at all. Right at the end, when she realizes that her daughters have to live here, and she has to live here for them, she has to say, this is my home. But right until then, she’s unable to express herself. That was the struggle Sarah and I always faced—how do you bring this about? Her character actually goes through a drastic change, but you don’t realize it from scene to scene because she doesn’t really express it. It’s all inside her. But by the end you do realize that there’s been this change.”

Or, as Gavron said, this awakening.