As the location for an interview about a film set in a hidden, run-down mansion without electricity but with peeling wallpaper and vines reaching through its open windows, the posh W Hotel in Downtown San Diego seems somewhat ironic. Especially when it’s a film that critically explores the ethics of consumer culture and the corporate system we are living in.

Lead actress and co-writer Brit Marling and writer-director Zal Batmanglij sat down with the Guardian to talk about their newest project, “The East,” a gripping espionage thriller that rapidly nabbed a spot on the list of most anticipated movies at this year’s Sundance Film Festival. They’ve been making their mark on the indie scene for quite some time now, with films like “Another Earth,” which Marling starred in, or “The Recordist” (directed by Batmanglij, also starring Marling). If those don’t ring a bell, their critically acclaimed 2011 psychological thriller “Sound of My Voice” might: a film about two journalists who want to debunk a cult led by the mysterious Maggie (Marling) but instead inevitably become ensnared by it.

“The East” plunges into the realms of subculture with Marling in the lead role. This time, she plays an overambitious agent, Sarah, who works for a private intelligence firm that helps corporations hide their crimes from the public. She is sent to spy on The East, an anarchist collective of eco-terrorists that tries to seek revenge on these corporations by beating them at their own games. Determined to bring the collectives to justice, she soon successfully integrates herself with the group. But the more time she spends with them, the more emotionally connected she becomes — especially with Benji (Alexander Skarsgard, “True Blood”) — and soon faces the moral contradictions of fighting for justice as an intelligence agent on the one hand and as an activist on the other.

“The East” is a film that raises many questions, but — deliberately — leaves out the answers.

“We are no message senders,” Marling said. “There was no way we were ever going to make a didactic movie with an answer for what should be done. I think it’s too hard to make sense of our times in order to have a prescription; we are so interested in the questions. We left that summer with more questions than we had answers, for sure.”

Consequently, Marling said, it is left to viewers to judge each character’s decisions and actions. We are carried along until we slowly begin to put ourselves in their positions, wondering what is right versus wrong.

“How far would you go to avenge your sister’s death at the hands of a corporation? If your father was responsible for harming people he had never met, would you be able to hold him accountable?” Marling asked. “If you are obsessed with the letter of the law, how far could you go to protect the man you love if his lifeblood is anarchy?”

Judging by these difficult moral questions, it would be wrong to peg “The East” as just another social issue movie, despite its provocative tone. In fact, it is primarily a multi-layered journey in which the characters are constantly stretched to their emotional limits. Take Sarah— whose initial image of a strong-willed woman slowly blurs while she is more and more forced to question her principles. 

“I don’t ever get any pleasure out of watching a sort of thinly discussed social commentary,” Marling said. “I love information. I love people showing me a world that I have never seen before and characters I have never met before, but I want them to let me think on my own. We try to be aware of that.”

They do it well — and it’s because they know what they’re talking about. After all, this film is not merely a product of thorough research about anarchist collectivists and their deliberate decision against conventionality: It stems from Marling and Batmanglij’s real-life experiences. Inspired by the “freegan” movement — the idea of embracing a community-based life that rejects the concepts of materialism and consumerism — they decided to spend a summer living off the grid, growing their own food, dumpster diving and becoming radically autonomous beings.

“We learned to train hop, and we started to work on a organic farm,” Marling said. “Once you fall in with travelers, you fall in with freegans; once you fall in with freegans, then, you find the anarchist collectivists.”

According to Batmanglij, these collectives pool in places all over the world.

“There are lots of anarchist groups all over Europe, Berlin especially. Big time. There are lots of squads, for sure,” he said. “It’s not something that most people have heard of, even in America. It’s a whole other lifestyle; it’s not like a hotel. You can’t just look it up and go there.”

The freegan “lifestyle” attracts people of many different socioeconomic backgrounds, sharing their anarchist manifestos, especially online.

“The beauty of the Internet is that it’s connecting all sorts of disparate groups together; all sorts of fringe movements are gaining the followers who really want to follow it,“ Batmanglij said.

This social diversity can also be seen in “The East,” in which a college dropout, a med-school graduate, a hacker, an ex-soldier, a street kid, etc. — all of them with their own personal reasons — join forces to fight for their beliefs.

Originally, Marling and Batmanglij did not intend to make a movie that examines the complexity of our society’s corporate structure.

“We were always very passionate about these [freegan] ideas in theory, but it wasn’t until we lived them that we really understood them emotionally,” Batmanglij said. 

Batmanglij particularly recalls the BP oil disaster in 2010 as both a driving and confirmative force in the writing process.

“Sometimes, confidence is the ingredient that you need to get going, and that gave us confidence,” he said.

It is this rich repertoire of firsthand experiences and profound investigation that make “The East” so authentic. But their summer on the American road wasn’t always fun. Batmanglij and Marling encountered many situations that took time to get used to — moments when both wanted to quit and go back to their conventional way of life.

Batmanglij recalls his most challenging experience: when his group found some broken bicycles, fixed them and went downtown toward the city’s fountain.

“We were playing around downtown, and it started to rain a little bit,” he said. “A few of us just started to take off their clothes and jumped in the fountain. You know, just having fun. I did not want get into that fountain.”

With the rain coming down, a long bike ride back and the definite prospect of an uneasy night on the floor with the squad ahead of him, Batmanglij would have had rather given up and taken a hot shower, but he decided to stick it out.

“The rain was pouring so hard — at some point, you just let go. You just break. Then, you look around and think: ‘I’m young. I’m not alone. I got my best friend and this whole community. Rain isn’t going to hurt me,” he said.  “There’s nothing to look forward to. There’s nothing in the past. There’s just this ride.’ You feel the wheels going and the rain hitting your back.”

The same is true of Sarah: A number of times, we see her on the brink of giving up, yet she always battles her way through. And although her final decision in the moment of truth is unexpected, it is meaningful in various ways. “The East” leaves it up to us to unravel its implications.