A long form love letter from a lifelong fan:

Now playing at the London Film Festival, excitement is bubbling over for Alfonso Cuarón's Gravity, with the IMAX 3D presentation talked up as an essential part of the experience. But before it bows nationwide, Britain's largest cinema screen is currently home to heavy metal titans Metallica, and their trippy 3D concert film Through the Never, a sonic thrill ride whose riff-laden rampancy is certainly less perilous, but like Sandra Bullock spinning in the black void, it rocks out of control with such intensity as to inspire breathless, stratospheric awe. It may not shred nerves but by God does it shred.

As a diehard metal fan who came thrashing into the world the same month and year as Metallica's debut album "Kill 'em All" the band's ups and downs have been intertwined with my own, a munchkin mosher from eight-years old. And like most Metallica diehards who aren't apologetically under the influence of their God-like status in the metal community, I have in recent years, learned to temper my devotion with the requisite amount of cynicism. In 1996, little did we know that cutting their hair and wearing make-up was only the tip of the iceberg. Since then we've had the Napster debacle, a solo-less album that sounded like it was recorded in a trash can, a feature length therapy session, the dare-not-speak-its-name collaboration with Lou Reed, and the transformation of front man James Hetfield from a hard-drinking, stage-stalking, ragged wolf to a sober judge, razor cut Rockabilly, tricked out in trucker tattoos and prone to vocal self-parody. A mortifying metamorphosis if ever there was one, something akin to the WWF's dead man "Undertaker" becoming the WWE's "American Badass" biker. And after sinking to shameless KISS-levels of merchandising with a recent Metallica pinball machine, this cinematic detour complete with gimmicky 3D, couldn't feel less like an artistic outgrowth so much as an extension of the brand.

The cheesy band member intros in the wrap around narrative don't instill much faith. Trip (Dane DeHaan) is an ardent fan-turned roadie, about to get his first backstage glimpse of his heroes. Vocalist James Hetfield riding by in a ZZ Top-mobile and dark sunglasses caused titters, and eyes rolled upon seeing bassist Rob Trujillo's pre-show-warm up, his patented spider crawl stomp, shaking the foundations of the practise room with the assistance of cheap looking CGI. But when Metallica finally take to the stage they own every inch of that IMAX screen, like only a band who've played the biggest venues in the world thrice over could do.

Mashing non-believers and jilted disciples within its first two numbers, Through the Never sees the group on inspirational form, a destructive circle of born-in-the-bones cohesion, pounding out aggression and whipping up a fury not seen since their arena slaying, world-conquering heyday. These songs have always sounded great but rarely this good. In what is undoubtedly one of the most dynamic sound mixes ever heard for a recorded concert (drummer Lars Ulrich was reportedly still making tweaks days after the Film's premiere at the Toronto International Film Festival), the earthshattering raw power is so immersive, the skull-stomping amplitude so loud, (yet so precise), it's like being thrown head first into a maelstrom of riffs whose vertiginous violence is heightened exponentially by the dangerously steep incline of the IMAX stadium seating, where no bottom is visible. Every time Hetfield peeled off atom bomb-sized power chords that rattled the row I was sitting in, I feared I might be thrown from my seat and plunge into the abyss below.

The closest they've ever come in the years since to the halcyon '93 era, the boys play as if their eponymous "Black Album" were still top of the charts and they're yet to complete the three year globetrotting tour which saw them become not just the biggest band in metal, but the world. Fitting then, that the concert sees a return to the theatrically that's been missing from "Load" onwards. The expansive floor panels and coffin-shaped lighting rig which adorns their gargantuan stage (specially built for the film), has been cleverly fitted with giant screens, displaying macabre visual interpretations of the most potent lyrics. A river of blood flows under the band's feet during "Creeping Death", and iconic cover art crosses rise up out of the floor for "Master of Puppets" with the coffins lit up to reveal people trapped inside. During "Ride the Lightning," an inmate is dragged from his cell to an electric chair, just as a chair the size of a three-storey building descends from the ceiling. All of this before the euphoric highpoint; a monolithic statue of Lady Justice is constructed piece by piece for "...And Justice For All", an opus played in its entirety and not in the medley form that's become a live staple for the last twenty years. A symphony of punishment the likes of Bach and Mozart would have conducted if they'd ever picked up guitars, Hetfield hands down an unfeeling sentence ("Justice is lost, justice is raped, justice is done") just as cracks appear in the statue which then tumbles down around the band, crystallising the track as their most epic, enduring and unfairly maligned master work.

Even on such a big screen, the scale of the production never dwarfs these larger than life performers. Cameras crane down from the ceiling in impressive arcs that dive headlong into the mayhem. One moment Rob Trujillo is seen from up high, but seamlessly, seconds later we're down amongst the crowd as he stamps right up to one of the barriers, gurning against a feeding frenzy of outstretched hands and devil horns.

You truly start to feel sorry for Trip and all he's missing, a serious head banging session interrupted early on when he's sent off with a can of gasoline to re-fuel one of the tour trucks and secure a mysterious package. En-route he gets in an auto wreck and finds himself right in the middle of a massive standoff between riot cops and a metal militia. Here the stage screens serve a double purpose as the portals that whip us from the gig to the narrative and back again, the connections as tenuous as the story is ill conceived. Save for a neat moment where the riot cops bang their truncheons on their shields in time with the steady-build intro of "Wherever I May Roam", a lot of the roadie footage fails to wow in the same way as the concert. Trip encountering a horseman of the apocalypse feels like short-change, as you're expecting to see the four of them from the song of the same name. And if a storyline that has Trip set himself on fire to escape a gang beating, only to appear in the next song on a random rooftop totally unscathed is going to be that nonsensical, then why not drug up the journey in a way that's more psychedelically abstract? Simply put, Trip's trip isn't trippy enough.

Thankfully, DeHaan has enough presence to keep us interested in Trip so that he doesn't become an irritation every time we cut away from the gig right in the middle of some righteous riffage. That he does so with barely a line of dialogue and only the intensity of his piercing, frightened eyes is even more impressive. He may not look like your typical meathead metal fan, but his gaze encompasses that nebulous feeling of ostracization that draws many of the marginalized masses to heavy music in the first place. And as someone who's been attending gigs most of my life wearing Woody Allen sweaters, never having had much taste for the cliché of garish black t-shirts baring offensive slogans, the casting of bookish, slightly effeminate DeHann (soon to be seen locking lips with Daniel Radcliffe in Kill Your Darlings) is really refreshing in not making the tired assumption of all metalheads dressing, looking and acting alike.

Unfortunately, this token of progressive thinking doesn't extend to the storytelling and on multiple occasions, the weave between music and narrative proves problematic. Right in the middle stretch we're treated to a triumphant old school triptych of "...And Justice For All", "Master of Puppets" and "Battery" that whiplashes the neck and fizzes the blood in furious fashion. It's during the third song that Trip stands up to the thugs who want his head. Setting himself on fire, he attacks wildly but can't resist their numbers. Gang members pile on top of him just as "Battery" reaches the crest of its heaviest wave, the perfect moment for him to find demented reserves of strength and smash through the hoard as if he were Neo in the Burly Brawl from The Matrix Reloaded. But no, instead, the best bit of the song is cut short and we inexplicably transition into Trip's headspace and a rendition of the ballad "Nothing Else Matters", which after the head charge rush of the previous three numbers, has never felt more unwelcome in a Metallica set list. It could have heralded a spectacular moment where "Battery" comes charging back in at the other end, with "Matters" playing like some kind of vision quest interlude, but the film's structure isn't bold enough to move beyond a locked list of songs.

The list itself is a fan-pleasing barrage of hits, better than any Metallica show in the last decade. "Cyanide" off the most recent album "Death Magnetic" is a genuine surprise, proving its muscular mettle against the classics and sounding tenfold meaner than it was on record. There are no complaints, save for the inclusion of the atrocious "The Memory Remains", a sludgy filler of a single with a half-speed hook that tries way too hard. It was terrible in '97 and it's cringworthy now, especially when you consider it being chosen over venue destroyers like "Sad But True" or Harvester of Sorrow". The film is called Through the Never for Christ sake, named after a militaristic monster off the self-titled album that's rarely, if ever played. Not doing so is a letdown for hardcore fans as well as a blatant oversight on the part of the band.

Skirting very close to classic concert status, it's been an age since Metallica sounded so rejuvenated, raw and relevant. For those who've steadily lost the faith since the new millennium, Through the Never is a rip-roaring reminder of their status as cultural icons and leaders in their genre. The heaviest band in the world has never sounded heavier.