Whenever the power goes out, it's hard not to wonder in the back of your mind if it'll ever come back on. The newest film by the Church of Scientology's least-favorite documentarian, Alex Gibney's Zero Days demonstrates that it's easier than you might think in our interconnected world for our power grid to be knocked out, or worse. Zero Days tells the story of Stuxnet, the most complex virus ever created as of 2009; it was developed by the NSA, in cahoots with Israel, to make certain centrifuges in Iran's Natanz nuclear facility spin out of control and go kablooey. It worked, but when the Stuxnet monster turned around and attacked American computers in a way that nobody could have possibly predicted — thanks for nothing, Mary Shelley! — the Department of Homeland Security didn't know it was coming from elsewhere in the U.S. government. Not only did the Obama administration refuse to acknowledge conducting online attacks until Edward Snowden spilled the beans, it turns out the first rule of communicating about such things between government agencies boils down to "Talk about Fight Club before you talk about cyber-warfare." Zero Days doesn't offer any answers, or even hope — how could it? — but at least it shines a light on a major, and majorly terrifying, issue.