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." 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 look of unbearable seriousness 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. by Brendan Kiley