When Oakland's Secrets of the Sky burst the national scene with To Sail Black Waters in 2013, they took virtually everyone outside the Bay Area by surprise.

Their brand of doom metal carried within it progressive touches and almost blackened atmospherics.

Co-founding keyboardist/guitarist Chris Anderson has departed from the lineup, leaving this unit a quintet, but it hasn't lessened the impact of their attack.

Pathway is not only as heavy as its predecessor it's more diverse.

Teaming again with veteran producer/engineer Juan Urteaga, the album is seemingly designed as a suite, with numbered interludes between the set's six proper tracks.

Sonically, these range from crashing ocean waves and wordless, reverb-laden vocal chants to groaning and horror-film sound effects.

Though different from one another, they succeed in presenting the songs as separate entities that make up the album proper.

Vocalist Garett Gazay displays a tremendous dramatic technique, control, and dynamic range, alternating between clean, howled, growled, and screamed vocals -- often within a single song.

Opener and second single "Three Swords" offers a repetitive, ringing, slightly staggered guitar pattern by Andrew Green and Clayton Bartholomew before Gazay begins in a melodic near whisper.

He increases his intensity with the gathering force of the guitars and bassist Ryan Healy before unraveling into a harsh roar as Lance Lea's drums (whose sound throughout is just enormous) explode.

Here, as in other tracks, Secrets of the Sky weave together Porcupine Tree-esque prog, My Dying Bride's brand of gothic doom, and Agalloch's blackness, with a transcendent dynamism and exploratory harmonic sensibility of their own.

First single "Angel in Vines" contains a guitar riff whose heaviness quotient is worthy of Black Sabbath; Gazay's menacing growl heads directly into the maelstrom delivered by the thudding bass and thundering drums.

In the bridges he slips clean, restrained singing supported by melancholy, dreamy guitars.

The axe riff from "Garden of Prayers" -- the set's longest track -- is borrowed from the Beatles' "Because," though it's turned and twisted into something far more menacing in Gazay's raspy-throated venom and the rhythm section's cacophonous interplay.

The cleaner vocal sections of the track are haunted by an enormity of despair and loss.

Given all the atmosphere at work here, the near industrial death metal force in "Fosforos" comes as a shock.

Gazay's vocals are all screamed amid triple-timed drumming, and the guitarists go at one another with angular, dissonant vamps.

After the hard, unforgiving, hypersonic "Eternal Wolves," a keyboard drone gives way to crashing waves and a cawing crow ushers in the silence.

Pathway delivers on the promise of To Sail Black Waters and proceeds from it by building a sound that, in its embrace of styles, textures, and shapeshifting architectures, is unique among American metal bands.