“This circle was a temple which had been devoured by ancient fires, profaned by the miasmal jungle, and whose god no longer received the homage of men.” So wrote Jorge Luis Borges in his short story “The Circular Ruin.” In it, a man undertakes a quest to dream a new person into being. He sleeps for months in the ruins of a temple that once belonged to a deity of flame, using wizardry and his slumbering visions to conjure a full-grown son, organ by organ, into existence. But his quest comes with a price: a shattering realization about the nature of existence, and of otherness, that’s too terrible in its geometric perfection to sanely abide.

Neurosis are no strangers to circularity and otherness. The Oakland-based post-metal collective turns 30 this year, though when its members convened in the mid-’80s, there was only a hint that they’d become the entity capable of creating their 1996 masterpiece, Through Silver in Blood. Neurosis’ debut album, 1987’s Pain of Mind, was a vicious, breakneck amalgam of crust and hardcore with fuck-the-system songs like “United Sheep” and “Life on Your Knees.” Pretty standard fare for the Reagan era, but it didn’t take long for the band to begin evolving—and rapidly. Each release, from 1990’s The Word as Law to 1992’s Souls at Zero to 1993’s Enemy of the Sun, progressed exponentially from the album before it. The addition, in 1989, of singer/guitarist Steve Von Till to the group’s core—singer/guitarist Scott Kelly, bassist Dave Edwardson, and drummer Jason Roeder—accelerated the band’s rate of experimentation. So did the recruitment of a full-time keyboardist and sample manipulator in 1990 (first Simon McIlroy, then Noah Landis, who has served since 1995), which proved that Neurosis’ hardcore chrysalis was something they were eager to shed.

The band’s ambition greatly stretched their canvas. After allowing metallic elements to creep into The Word as Law—an album released on Lookout! Records, which made Neurosis, oddly enough, labelmates with Green Day—a far more sprawling vision informed Souls at Zero and Enemy of the Sun. The three-minute salvos of Pain of Mind were gone; in their place were staggering opuses like “Cleanse,” which ends Enemy of the Sun on a 26-minute, Crash Worship-esque eruption of chants and tribal percussion. Lyrics no longer concerned themselves with middle fingers raised at modern society. Instead, a sense of pagan awe seeped into Neurosis, to the point where the straw-effigy cover art of Souls at Zero drew inspiration from the pagan horror film The Wicker Man. Tellingly, the final ten minutes of the album comprise a maddening, heavily effected vocal loop that bounces from speaker to speaker, a hint of the unsettling circularity of their next album: Through Silver in Blood.

In addition to the band celebrating its 30th anniversary, Through Silver in Blood turned 20 earlier this year. It’s an album of cyclical mystique. Like “The Circular Ruin” and so many other Borges stories, Through Silver oscillates like an intricate orrery of loops within loops, contained by even greater loops—elusive and extra-dimensional. Whether intentional or not, the album’s closing track, “Enclosure in Flame,” evokes “The Circular Ruin”: “I will open a door and bleed in your dreams,” go the words, howled over a churning, gargantuan guitar motif before concluding, “Silently praying for enclosure/Within the flame of origin.”

“I’d say this record is more of an epic undertaking than the last one,” Dave Edwardson said in a 1996 interview, speaking about Through Silver. It might have been the understatement of the year. Neurosis’ fifth full-length isn’t just a proclamation; it’s a monolith. At the height of the CD age, when bands felt obliged to push the format’s data capacity to the limit, the album uncoils accordingly—a 70-minute odyssey into inhuman realms of weirdness. The title track is a layering of tidal sludge, depth-of-hell screams, and undulating lurches of riffage. “Eye” roils like a weaponized storm; “Aeon” lulls with a cello-and-violin-spiced, chamber-folk intro before going seismic.

Infamously, the scathing sheets of discordance that punctuate “Purify”—not to mention the bloodcurdling refrain of “sacrifice the flesh,” which sounds less like a commandment and more like an ecstatic release—give way to the most ethereal bagpipes ever committed to record. They’re made all the more arresting for their sonic and cognitive dissonance, sounding a bit like an ancient incantation reverberating through the centuries. On “Locust Star,” which remains a staple of Neurosis’ lives sets, the earthly corruption of religion is thrown on a bed of nails: “Your belief is scars.” In the hands of a younger Neurosis, it would’ve been just another hardcore screed; here it’s poetic and ambiguous, a probing of the theistic impulse with the tip of a dagger.

The pieces of each song are simple, if not downright elemental—but they’re locked together to form a complex apparatus of mud, bone, and stone. Synths, samples, effects, and amplification are bent toward a paradox. Unlike Radiohead’s comparably vast and innovative OK Computer from the following year, technology isn’t used to comment on the alienating nature of technology; instead, technology is used to mask its own inherent coldness. Organic yet mechanistic, dense yet severe, Through Silver is industrial music as it might have been imagined by a preindustrial people.