As he closes in on his seventieth birthday, maybe Danny Boyle is thinking about legacy. For a filmmaker who spent most of his career, through good and bad films, constitutionally averse to repeating himself, it’s notable that two of the last three bigscreen features he directed are sequels to commercial and critical triumphs from more than two decades earlier. Combined with his wholly admirable recent concession that there were more culturally appropriate directors for Slumdog Millionaire, the film that won him an Oscar, it seems Boyle is in a process of uniquely thoughtful professional reassessment.

Maybe the most amazing thing about this retroactivity is that Boyle has emerged with striking and interesting new works. I was already shocked to discover that T2 Trainspotting, the follow-up to Boyle iconic 1996 breakthrough, was energetic and inventive. Now, he reacquaints himself with the society chucked into chaos by feverish, zombie-like figures that he introduced in the 2002 film 28 Days Later, and it also proves to be weirdly winning. The third film in the series, 28 Years Later, returns Boyle to the director’s chair and also brings back Alex Garland as the sole credited screenwriter, after both were more tangentially involved with the first sequel, 28 Weeks Later, released in 2007. The collaborators take full advantage of the healthy distance from their original outing in this grim, bloody storyline.

If the timeframe of the first film’s titles suggests a beset community still raw from the shock of the gruesome danger they’re enduring, swapping Days for Years means people who’ve grown at lest somewhat accustomed to ravenous flesh-eaters always at the ready to mindlessly sprint towards their next meal. In a grim joke, most of the world has fully moved on from the incurable disease, dubbed the Rage Virus, that creates the zombies. Only Great Britain remains beset by the ravaging beings, the result of a quarantine. There, a group of survivors lives on an offshore island in relatively safety, only journeying to the treacherous mainland for occasional snagging of resources and evidently a few questionable rites of passage. It’s the latter that leads to twelve-year-old Spike (Alfie Williams) crossing the land bridge with his father, Jamie (Aaron Taylor-Johnson), to hunt infected marauders.

As happens when youngsters are pushed into growing up, Spike begins to question everything he knows, including whether others are being honest with him about the health of his mother, Isla (Jodie Comer), who’s prone to debilitating headaches and accompanying mad raving. Spike begins to suspect that there’s a way to cure his mother after he’s told ominous stories about a person who lives on the mainland named Dr. Kelson (Ralph Fiennes).

While adhering to general, sturdy themes about the precarious nature of society and how reliant it is on agreed-upon deceptions, Boyle and his collaborators cram four or five different movies into 28 Years Later. There are plenty of gory encounters with monsters whose humanity has been rotted away by the Rage Virus, mostly shot and edited in an aggressive, kinetic style that is reminiscent of the first film and appears to interest Boyle the least of anything happening here. There is also viciously intense family drama that is hampered by Taylor-Johnson’s mediocre booming and improved the more it tightens in on the far superior acting of Williams and Comer. There’s a tried-and-true quest narrative and then Fiennes take prominence with a carefully crafted turn that brings the film into the realm of warmly nihilistic philosophizing. None of that begins to reckon with the last five minutes or so of the film, which are right on the verge of being completely out of control, in a good way.

I don’t know if Boyle coheres the clanging, disparate components of 28 Years Later into a film that rewards scrutiny beyond registering the jolt of its freewheeling creativity. For even the boldest movies, too many left turns leads to simply driving in a circle. Of course, when the pedal is pressed all the way done, that kind of route can be dizzying and exhilarating, too.