In 2019, the questing young dudes of King Gizzard & The Lizard Wizard cracked open the door that led to full-on thrash-metal nirvana with their concept album Infest The Rats’ Nest. The LP allowed the group to tap into their inner metalhead, to commune with the pre-teen heshers they’d once been. An off-the-cuff experiment, …Rats’ Nest went on to become one of the group’s favourites among their discography, and the album’s neck-snapping, devil’s-horn-throwing anthems remain highlights in Gizzard setlists to this day, stirring moshpits into ecstasy every night.

It had been intended as a one-off, but ever since that maiden voyage into the feral wastelands of thrash, the Gizzard have heard the siren call of metal in the wind. Their 2022 post-pandemic epic Omnium Gatherum featured two righteous blasts of tungsten riffage and scourged-throat incantations, Gaia and Predator X. Consider them the patches of fur that appear on the forearms of a man-wolf, signalling their transformation is nigh.

Because, to extend the metaphor, Gizzard’s next album – their 24^th, if you’re the kind of poindexter who keeps score – is where the moon becomes full and their gnarly lycanthrope-selves take control again. For PetroDragonic Apocalypse; or, Dawn of Eternal Night: An Annihilation of Planet Earth and the Beginning of Merciless Damnation is the group’s second album-length excursion into thrash – though, as you might expect from such a restlessly creative unit, it’s no mere retread of …Rats’ Nest’s gory glories, but rather a full evolutionary step all its own.

“When we made …Rats’ Nest, it felt experimental,” says Stu Mackenzie, Gizzard King. “Like, ‘Here’s this music that some of us grew up on but we’d never had the guts or confidence to really play before, so let’s give it a go and see what happens’. And when we made that album we were like, ‘Fuck, why did it take us so long to do this?’ It’s just so much fun to play that music, and those songs work so well when we play them live. So we always had it in our minds to make another metal record.”

However, the group were wary of repeating themselves. So when Gizzard’s core trio of metal-heads – Mackenzie, Joey Walker and drummer Michael “Cavs” Cavanagh – assembled to begin writing these songs, they approached this project in a radically different way. “We worked on it the same way we started our Ice, Death, Planets, Lungs, Mushrooms And Lava album last year,” says Mackenzie. “We wrote a song a day, and we came into the practice space with no riffs, no tunes, no ideas, and started from scratch. And we jammed, and recorded everything, and pieced the songs together from that. I’d sketched out the story the songs would tell, and I’d portioned it out into seven song titles, with a short paragraph of what would happen in the song. I guess we kind of made the record backwards.”

While Mackenzie had conceived the original skeleton of the story, he tapped his bandmates to write additional lyrics to each song communally. “It was really challenging to assemble all these different voices,” says Mackenzie, “because everyone was naturally writing from a different perspective, often from a different character’s point of view. But it was a lot of fun, too. Part of the challenge was to fill it all in, to make it all make sense, which I fuckin’ loved. It was like constructing a house out of sticks. From the music to the lyrics, it was the most deconstructed thing you’ve ever seen, all this random psychobabble and dark poetry and wild riffs. Our mindset was, ‘Let’s piece this all together into something that will freak people out’.

PetroDragonic Apocalypse owes a lot to fantasy lore, as the title suggests. “We wanted to start the story in the real world, and then send it to hell,” grins Mackenzie. “It’s about humankind and it’s about planet Earth but it’s also about witches and dragons and shit” he laughs. Lyrically, PetroDragonic Apocalypse is fun on the surface, but profound if you dig a little deeper. Shakespeare and the Bible were definite inspirations for the voice of some of the lyrics, which play out the album’s blackly comedic and bleakly destructive tale with the highest of drama. It’s like a secondary voice on the album – it appears in each song, and it’s like words that were spoken 500 years ago, or 2,000 years ago.” The music of PetroDragonic Apocalypse, meanwhile, features Gizzard’s finest thrash-flavoured riffage yet, channelling the razor-sharp, prog-influenced vibe of the genre’s late-80s apex – super-complex but also brutal-as-f***.

It won’t surprise anyone who’s been paying attention that King Gizzard have also almost finished work on their next album, another seven-track concept record that was begun around the same time as PetroDragonic Apocalypse, and followed its improvised, one-song-a-day method. “I’m not a tortured artist, I’m more of a mad professor,” admits Mackenzie. “And after a bunch of records crafted out of jams, we’re very much ready to make records in the old-fashioned way of writing the songs before we enter the studio, once these ones are done.”