Here’s what it sounds like when the voice of reason is screaming at you: first like a thick swish of water being violently sucked down the drain; then like the protracted shriek of a garbage truck as the driver slams hard on the brake pedal; and finally like words, rendered in impossible blasts of human breath, announcing a counterintuitive truth: “Lucidity has found me.”

The lucid screamer was Liam Neighbors, the heavy-metal auteur behind the Oregon group Mizmor. The song was “Desert of Absurdity,” a 10-minute opus inspired by Albert Camus’s “The Myth of Sisyphus,” a philosophical essay that confronts the absurdity of existence via that old Greek story about a doomed ­boulder-pusher.

As for the performance itself — at Atlas Brew Works on Wednesday night — it was extraordinary: dense, demanding, tempestuous music delivered with a composure that felt something like grace.

It took Neighbors a few years to roll his boulder up here. He founded Mizmor in 2012 while struggling with his Christianity and began writing songs as a means of grieving his disintegrating faith. Since then, his music has only grown more intense, sonically and philosophically. Mizmor’s new album, “Cairn,” is about figuring out how to live your life in the present moment,” Neighbors recently told Metal Injection. “It’s anti-God and anti-suicide, and actually a very positive affirmation of life, even though it sounds very grim.”

That spiritual arc is connecting with metal-inclined listeners who feel betrayed by religion. But Mizmor’s wider proposition might resonate with anyone who feels abandoned by their government or imperiled by their warming climate. What’s astonishing is how Neighbors funnels so much clarity and despair into guitar phrases that torque time and space. Onstage, Mizmor’s most lumbering riffs didn’t make time feel slow; they made gravity feel like it was pulling down twice as hard. Similarly, when the tempos sped up, you didn’t feel rushed so much as crushed.

The gears shifted most dramatically during “Woe Regains My Substance,” a sprawling cut from 2016 that felt amazingly loud and completely disorienting. “Beginning and end seem synonyms,” Neighbors growled, sure-footed at the center of the sensation. “Impossible to trace and nevertheless infinite.”

A few moments later, during an expressionless daze of interstitial shredding, he bent a note on his guitar, superimposing a playful scribble onto an otherwise stoic moment. Then his mouth bent into a little half-smile. Like Camus wrote, “One must imagine Sisyphus happy.”