THE PHOTOGRAPHS tucked inside the liner notes of Agalloch's fifth album, The Serpent and the Sphere, frame the quartet against the backdrop of the natural world, where they're dwarfed by huge rock faces, menacing-looking icicles, and the vastness of the night sky. It's a fine visual corollary for the themes of The Serpent's lyrics. Through nine tracks of trauma-inducing blastbeats and skin-peeling guitar solos, frontman John Haughm growls out an array of expansive imagery. In "Vales Beyond Dimension," he arrives "at the corridor of infinity/ the great hall where the ages are kept," and he marvels at, as the title of another song goes, the "Birth and Death of the Pillars of Creation."

"For this album, I wanted to explore some metaphysical subjects that I have been interested in for a while," Haughm writes via email. "How our existence in the universe is so astronomically minute and pathetic in the vastness of space and time, but at the same time, an entire micro-universe exists within us that is equally vast and complex. There are references to the destruction of a nebula formation 6,000 years ago [and] death as a DMT trip."

The staging of the photos also reflects a placidity that has crept into the black metal's music since 2012's Faustian Echoes EP, although with The Serpent, the clenched fist of their earlier work seems to be completely unfurled. The album is intercut with gorgeous acoustic interludes played by folk musician Nathanael Larochette, and melodic textures that reveal a post-punk influence.

Haughm agrees with this, noting that Agalloch's previous full-length, 2010's Marrow of the Spirit, carried with it a tone of discomfort due to a combination of factors.

"It was the first album away from the End Records, with a new drummer [Aesop Dekker, who is still with the band], in a totally new studio, and with a producer/engineer [Steven Wray Lobdell] who we'd never worked with previously," Haughm writes. "You can definitely hear the tension in that recording, which, in hindsight, actually helped make that album what it was."

As they've moved forward since Marrow, Agalloch has sounded more unified and resolute than ever. You can sense this development in the band's live performance; their last local show—in October 2013 at Star Theater as part of the Fall Into Darkness festival—carried with it the breadth and power of a natural disaster. Their recent tours in Europe and the US have only intensified the anticipation for The Serpent's release.

The impermanence of all things—on this planet and beyond—is a further theme that haunts Agalloch's work. The band finds charge and weight in exploring the fleetingly transient and cyclical nature of things. In Haughm's view, it's something to be embraced rather than feared.

"I look to the void with the same wonder and awe as I once did with nature," he writes. "Everything ends. Everything returns to nothingness and energy. That is really the only conclusion that cannot be contested. I find it really fucking inspiring."