For a film that largely takes place in a Hong Kong hotel room, Laura Poitras's Citizenfour—a deeply embedded documentary about Edward Snowden's revelations of the US's extensive spying program—is a gut-clenching thriller. It begins with the camera rushing down a black tunnel and Poitras reading from one of the early e-mails Snowden sent her: "At this stage I can offer nothing more than my word. I am a senior government employee in the intelligence community. I hope you understand that contacting you is extremely high risk... This will not be a waste of your time."

After a few e-mail exchanges, Snowden (who was signing his e-mails "citizenfour") tells Poitras to meet him in the restaurant of a Hong Kong hotel. He will be playing with a Rubik's Cube, they will have a scripted exchange, and she will follow him. Minutes later, she's turned on her camera and we all get to watch as he shows her and journalist Glenn Greenwald exactly how the US government is "building the biggest weapon for oppression in the history of mankind."

It's a truth so big, the public still hasn't fully digested it—one can tell by how quickly we shrugged off the idea of totalized surveillance as either necessary or inevitable. As computer security researcher and activist Jacob Appelbaum says during a panel discussion in Citizenfour: "What people used to call liberty and freedom they now call privacy—and in the same breath, they say that privacy is dead." But Citizenfour walks us through the facts and their implications, from Snowden sitting on a bed and patiently explaining how the vast majority of communication between devices is indiscriminately "ingested" to showing clips of intelligence officials stonily lying during congressional testimony.

In one chilling scene, Senator Ron Wyden asks Director of National Intelligence James Clapper, "Does the NSA collect any type of data at all on millions or hundreds of millions of Americans?" When Clapper answers, "No, sir," Senator Wyden leans forward and asks, sounding stunned, "It does not?" This was before the Snowden revelations, and Senator Wyden, as a member of the Senate's intelligence committee, knew the answer to his question—and that Clapper knew he knew, but chose to lie anyway.

Throughout the film, Snowden insists that he is not the story. He knows his identity will have to be revealed eventually—in part to protect others who might fall under suspicion and in part to tell the surveillance state that, in his words, "You're not going to bully me into silence like you've done to everybody else"—but calmly insists on minimizing himself. Poitras, while honoring that request, gives us small glimpses into Snowden's world: a copy of Cory Doctorow's novel Homeland on his nightstand, him cracking a tight smile and asking "Nervous?" after what sounds like Greenwald dropping his pen off-camera at the top of their first tense meeting, and his grim expression at the end of his sojourn in Hong Kong as he faces the fact that in a few minutes he's going to have to leave the hotel and run, possibly for his life.

Throughout Citizenfour, Poitras masterfully balances her reporting with the human implications. She is able to capture brief and ominous shots of data complexes in Germany, Britain, and the US, and traces the arc of Snowden and Greenwald becoming more savvy and more careful. Toward the end of the film, Snowden, Greenwald, and Poitras reunite in Moscow, where they talk in snippets of words and snippets of handwritten notes. (Al three know they are some of the most sought-after surveillance targets in the world, and that even speaking sensitive information out loud is a risk.) Greenwald says they have a new source that shocks even Snowden. The camera flashes across pieces of paper that mention drone strikes out of Germany, 1.2 million people on watch lists ("That's fucking ridiculous," Snowden says incredulously), and unspecified decision-making charts Greenwald has seen that all point to a box that says "POTUS."

This story is not over. recommended