While 28 Days Later cuts a chilling swath through the notions of our sense of global safety from a virus, it also packs an unexpectedly moving punch related to its humans and the comforts they cling to.

Yes, it has fast-running, flesh-craving zombies who sprint and leap after their prey. But the story’s humans aren’t merely dumb fodder for the creatures. Director Danny Boyle and writer Alex Garland astonishingly balance this blend of shock-tactic scares and quiet introspection.

The film opens in an animal lab in London where monkeys are being forced to watch beatings, riots and other human atrocities a la Alex in A Clockwork Orange. Animal activists infiltrate the lab and, despite a scientist’s warnings that the monkeys have been infected with highly contagious “rage,” release them anyway.

Through the next blood-covered two minutes, we learn just how big a mistake that is. After that frenzied opening, we cut to Jim (Cillian Murphy), a bicycle courier who wakes up entirely alone in a London hospital.

Taking to the deserted, detritus-laden streets, Jim is attacked by a group of “infected,” but spared and saved by the sassy Selena (Naomie Harris). Jim, who had been in a coma following an accident, learns that all of England has been overrun by the infection. 

Along with Selena, burly Frank (a stellar Brendan Gleeson) and Frank’s daughter, Hannah, Jim journeys to a military outpost near Manchester that promises the “answer to infection,” but turns out to be far from paradise.

The film has some smart, very unsettling scares as well as some nasty horror fun with the infection’s particulars. It takes hold in 20 seconds and can be contracted if infected blood gets in your eye, nose or mouth. (That the zombies vomit blood makes the latter possibility considerably more dangerous.)

And Boyle does not skimp on furious attack scenes, most notably a firebombing on the London streets and a close call in a long, dark apartment staircase. But during the first two acts, Boyle consistently finds a perfect release for this seemingly unrelenting tension in his film’s dramatic scenes and visual beauty.

Jim makes a discovery at his parents’ home that is played out in almost complete silence, but is as incredibly moving as anything else in a film this year. And after Frank administers a violent zombie beating, he retreats to the warm Christmas lights and music of his apartment, offering up drinks and company.

Whether it’s crème de menthe or a cheeseburger, the comforts this group of vagabonds clings to are what makes us identify with them. Because of the infection’s quick nature (and the fact there are no big stars), we don’t know who will be killed when, and it’s just as quick a shock to the audience as it is to the other characters.

Filmed using digital video, 28 Days Later has a grim but beautiful blurriness to it and a watery quality that makes for painterly brilliance in several wide shots. It’s reminiscent of Apocalypse Now, a sort of hallucinatory, bombed-out hell playing host to an uncertain journey.

Like that film, 28 Days Later plays itself out at a military encampment where lunacy has prevailed. And what steam it loses during its ho-hum, run-through-the-spook-house climax (complete with a raging storm outside) is at least not enough to lose us completely.

It’s a good thing that 28 Days Later is not merely a clone of George Romero’s Living Dead trilogy. The wide-eyed cynicism of those films kept them from being anything more than extremely well-executed pulp and social commentary.

Boyle’s vision is comparatively one of hope, remembrance, sadness and loss. The result is one of the year’s finest, a film that pushes forth all the scream-and-jump fun of a horror flick, but offers a human resonance that lingers longer than any of the scares.