Featuring an all-Norwegian cast, the film opens with the methodical planning and execution of the attack by white nationalist Anders Breivik (Anders Danielsen Lie), who set off a bomb within Oslo's government quarter before boating to an island that housed an international youth leadership camp, gunning down 69 helpless victims.Among those to survive is Viljar Hanssen (Jonas Strand Gravli), despite being shot multiple times, putting him through the torment of attempting to recover, despite shell fragments that remain perilously lodged in his brain.Those two stories comprise the central pillars of the film — which Greengrass wrote and directed, based on the book "One of Us" by Åsne Seierstad — but are augmented by two others: the defense attorney (Jon Øigarden) who Breivik requests, subjecting his family to death threats; and Norway's prime minister, Jen Stoltenberg (Ola G. Furuseth), who must struggle to maintain the nation's character and commitment to openness in the wake of the sort of incident prone to trigger knee-jerk responses."I knew I would need a lawyer one day," Breivik tells the attorney, with a chilling sense of serenity, expressing satisfaction at having slain so many "children of the elite."Having directed "United 93," the movie about the Sept. 11 attack, as well as "Captain Phillips" and "Bloody Sunday," Greengrass is something of a master of fact-based disaster. The challenge here is to make the movie more than just a grisly reenactment of those events or to glorify the lone-wolf perpetrator.Those issues remain open to debate, but "22 July's" no-frills approach sustains the various plots, while engaging in a thoughtful discussion about how to process such events, with Breivik's insanity defense prompting a newspaper headline within the movie that asks, "Insane or Just Evil?"Ultimately, "22 July" doesn't offer any easy answers, though it does find a ray of hope, delivering the not-so-subtle message that such extremists can only win if we let them.Viewers might come away with conflicting perceptions of whether Breivik is insane or just plain evil, but strictly in terms of the way Greengrass has structured the story — provoking thoughts that go well beyond the tragedy in Norway — there's clearly a method in the madness."22 July" premieres in theaters and on Netflix on Oct. 10.