Modern documentaries tend to gussy themselves up like a school filly with fancy new ribbons, trying to make the viewer feel like they're watching a tasty narrative film as opposed to eating their cinematic vegetables. Laura Poitras' Citizenfour has no such concerns; it's not adorned with graphics beyond tiny intertitles, occasional IM conversations, and the strangely beautiful gibberish of an encryption code, and for most of the running time the music is a single track from Nine Inch Nails' instrumental Ghosts album. This asceticism is not a bad thing, particularly since the subject is Edward Snowden, and the time period covered is when he famously blew the whistle on the NSA and became persona non grata in America. Citizenfour's centerpiece is Poitras and journalist Glenn Greenwald interviewing Snowden in June of 2013 in Hong Kong — the image you have in your head of Snowden? That's from Poitras' camera — and Poitras lets the footage breathe, particularly as Snowden explains just how thoroughly our government violates the world's privacy. He disappears for much of the second half to go into exile, but his presence remains, particularly as Poitras and Greenwald find their own lives being disrupted. And if Citizenfour ends abruptly, that's only because the real-life story is still far from over.