A follow-up to Boyle’s galvanising 2003 horror thriller “28 Days Later” and its 2007 sequel “28 Weeks Later,” “28 Years Later” (which at one point was supposed to be titled “28 Months Later,” but someone got distracted) asks questions surprisingly relevant to our current moment.

Such as: where does civilisation go at a time of societal collapse? How do a people maintain normality? What place does kindness have in a world of rampage and insanity?

These are deep and welcome thoughts for a zombie movie.

Although, right, they’re not technically zombies.

As posited in the original film, a laboratory-made “rage virus” has escaped, turning England into a mob of ravenous, kill-crazy cannibals, able to pass a fast-acting infection with a bite or even a drop of saliva.

By the time of “28 Years Later,” all of Britain has become one giant quarantine zone, its waters patrolled by an international coalition and outposts of humanity clinging to the coastline like life rafts.

One such community is Holy Island, connected to the mainland by a causeway that surfaces only at low tide. The islanders have made a life for themselves as a village of hardy, inventive survivors who come ashore to forage and pick off the infected where they can.

The film’s hero, a 12-year-old boy named Spike (Alfie Williams), makes the journey with his father (Aaron Taylor-Johnson) in the early scenes of “28 Years Later,” marking his first kill with a bow and arrow.

The ghoulies have evolved over the years into various types, including creepy crawling fatties who live on a diet of worms and strapping “alphas” who like to rip off heads with their spines attached.

In Williams’ sweetly sensitive portrayal, Spike is brave but also terrified, and he checks out of a celebratory party on his return to look in on his mum, Isla (Jodie Comer of “Killing Eve”), who’s bedridden and delusional from a mystery ailment.

The meat of the movie consists of the boy deciding to lead his mother toward a rumour of a doctor on the mainland, through a gauntlet of naked, frothing beasties with the occasional assist from a random human (Edvin Ryding, quite funny as an exasperated Swedish soldier).

Along the way, Spike and we, learn new things about zombie obstetrics and related matters.

Despite Boyle and co-screenwriter Alex Garland (writer-director of “Ex Machina,” “Civil War” and other provocations) returning to this property – and despite Boyle’s usual bag of tricks with stutter-stop cinematography and gruesome flash-cuts – “28 Years Later” lacks the visceral shock and relentless pace of the first two films (the second was directed by Juan Carlos Fresnadillo and written by a team that didn’t include Boyle or Garland).

Nor do the logistics of the film’s reinvented universe bear much scrutiny.

(What do the infected feed on if there are no normal humans left? Why are there still youngish ones after three decades?)

Instead, the tone is one of finely wrought mourning punctuated by bursts of adrenaline, with the relationship between mother and son given real emotional weight.

The camerawork by the great Anthony Dod Mantle (“Slumdog Millionaire”), a brooding score by the Scottish progressive hip-hop trio Young Fathers and some gob-stopping Highlands locations all raise the movie above standard fright-night fare.

And when Fiennes appears, “28 Years Later” becomes even more clearly a meditation on what comes after humanity’s downfall – what memories we save and who we choose to love and remember.

There’s still enough flesh-rending and severed body parts to sate the average horror fan.

More crucially, “28 Years Later” has enough meat on its bones to serve as more than just a warmup for the next instalment, due in 2026 and possibly featuring the original movie’s star (and this one’s executive producer) Cillian Murphy, who has gone on to bigger things in the intervening 22 years.

You do get the sense that this party is just getting (re)started, though, with a cliff-hanger ending that doesn’t leave the audience twisting in the wind, as such things often do, but instead introduces a character who threatens to take the next films into appealing looney-tunes territory.

I’d tell you more, but then I’d have to eat you.

Verdict: Three stars out of four.

28 Years Later is in New Zealand cinemas now.