Told in urgent fashion with first-hand accounts from cyber professionals from around the globe, Zero Days is a fascinating and alarming documentary about the Stuxnet computer virus. Originally codenamed “Olympic Games” by the people that fathered the worm, Stuxnet is a virus in the true sense of the word. It not only maliciously feeds off the host, but it also replicates itself as soon as it is implanted, which is exactly what it did when it was used by the US and Israeli secret services to sabotage centrifuges inside Iran's Natanz nuclear plant—making them spin out of control. All this is brilliantly unpacked by renowned documentary maker Alex Gibney (Going Clear, Enron: The Smartest Guys in the Room), who manages not only to detail the complexities of advanced coding in a remarkably evocative manner, but also to send out a well-researched alarm call about the future of war. Ultimately, the message here is that cyber warfare is very much part of our new shared reality. This film deserves to be seen by anyone who is even remotely concerned about global security in the 21st century.