When I spoke on the phone with Raposa earlier this year, as part of my research for a Castanets feature that ran here in the Guardian, two musicians' names were mentioned in the most reverent of tones: country music legend/king-of-heartbreak Hank Williams, and Swans/Angels of Light abyss-explorer Michael Gira.

Both reference points made sense in the context of Raposa's road-wandering spirit and unflinching depictions of depression and emotional paralysis, so eloquently expressed over the course of the three albums released under the Castanets moniker at that point - but with City of Refuge, the relevance grows considerably stronger. A darker-than-dark, weary-blues country spirit wheezes and croaks the choked breath of Hank Williams' ghost all over the disc, while the cold purity of desolation contained here is akin to the riveting isolation epics for which Gira has become legendary over the years.

Frequently accompanied by little more than the steady strum of an acoustic guitar or the scraping, reverb-slapping sounds of its electric counterpart, Raposa's anguished rasp - already an evocative instrument in its own right - takes on the role of a survivor at the end of the world, real or imagined. Yes, the long-familiar device of spaghetti-western guitar is employed to convey the sands and snakes of the merciless desert, but here the sounds arrive so disembodied that they appear to be produced not from the hands of mere man but rather ripped from the ground itself.

Or, worse yet perhaps all of these squalls and scrapes are simply echoes inside the sun-baked cranium of the narrator, roaming about in an unforgiving, shelter-less wilderness? Having just finished reading Cormac McCarthy's Pulitzer Prize-winning novel The Road, I couldn't help but be reminded of the devastating post-apocalyptic landscapes of the book as I descended deeper into City of Refuge's absorbingly bleak visions. Much like McCarthy's unnamed protagonists - simply referred to as "the man" and "the boy" in the novel - Raposa's narrator wanders alone in the barren nothingness, fiercely trying to hold strong to his humanity in the face of such adversity. To call it a struggle is a bit of an understatement: he often sounds like a man on the verge of crumbling underneath the weight of it all.

Perhaps in order to call further attention to the unpopulated landscape, Raposa doesn't even utter a single word until the fourth track on City of Refuge. The disc begins with a trio of instrumentals seemingly transmitted from some of the least forgiving spots on earth. Actually, this assessment isn't entirely true.

Opener "Celestial Shore" is a one-minute marvel of ringing electric guitar melodies giving way to echo-laden reverb ripples, thus evoking visions of Robin Guthrie sending shimmers across the Mojave Desert. It's a gorgeous piece, almost suggestive of hope - a quality occasionally hinted at here and there, but rarely as directly and unapologetically as on these opening 62 seconds.

From there, the last chimes of guitar give way to "High Plain 1," the first of three installments of eerie electronic blips and burps scattered across the album. The notes pop and ricochet, bouncing back and forth between monolithic rock formations and impossible cliffs. Meanwhile, an ominous hum hovers in the background, giving out the odd hiss and moan before receding under all the insistent torrent of squeaks and squawks. The results are frighteningly effective in portraying a world after the end-of-the-world.

Repeating such a jarring, confrontational device three times over the course of the disc was a risky proposition, but the triptych works wonderfully in heightening the nervous dread each time the nail-biting electronics are introduced. The third track, "The Destroyer," joins sighing spaghetti-western guitar with subterranean bass rumbles and belches and creep-inducing death-rattle shacks of bells. Troubling stuff. Close your eyes, and can almost smell the carrion baking in the sun.

The first vocal track, "Prettiest Chain," finds Raposa unveiling a theme that runs deeply throughout the disc: the desire to become unstuck, to break free, to set into motion. After asking his beloved, "Give me your prettiest chain to wear," he goes on to beg eagles for their wings, hoping to move beyond whatever is holding back.

Accompanied by little more than understated banjo and the haunting electric guitar refrains of "The Destroyer," he arrives as a man struggling to keep it all together. The occasional choked-blues cries of guitar, however, allude to the potential for violence in a manner strikingly similar to the early work of Nick Cave and the Bad Seeds.

The comparison hardly subsides with the follow-up, "Refuge 1," in which Raposa rasps out desperation in the form of unrelenting repetition of the phrase, "I'm gonna run to the city of refuge," over a malicious guitar pattern. Not only does the unhinged mantra bear the same message as Cave's Blind Willie Johnson-inspired psycho-blues "City of Refuge" (from the 1988 Mute stunner Tender Prey), but the song also stalks along with a similar threatening spirit.

"Glory B" - boasting sublime harmony vocals from Jana Hunter - fashions gripping human drama from the simplest of elements. The track uses little more than mesmerizing acoustic guitar patterns - slightly reminiscent of Jose Gonzalez's austere expressionistic playing - and the odd sporadic fit of clanging electric guitar bursts forth from seemingly out of nowhere. Raposa's vocals are thrust to the front of the mix, each syllable painted with shivering touches of echo. The recurring theme of movement makes a return appearance: "You've got a wandering heart / you've got wandering eyes / I wore myself out / just wanting you."

A zither-and-acoustic-guitar reading of the traditional ballad "I'll Fly Away" lightens the mood considerably - particularly after the unsettling rattlesnake-hiss of electronics on "High Plain 3" - thanks to Raposa's reverent, head-held-high delivery.

The song is followed by "The Hum," a thrilling desert-melodrama-in-miniature powered by Spanish guitar. Throw in some mariachi horns, and this instrumental could easily be mistaken for Calexico or Ennio Morricone.

The jittery, electric-guitar-stabbing "Savage" fits somewhere between the deranged lurching blues of early Nick Cave and the soul-baring howl of Swans, thanks largely to the conviction with which he makes the unrepentant confession, "I dreamt I was a savage / someday I am a savage / today I am a savage." All the while, bass notes pounce and pummel as scraps of jagged metal rip free from each clanking attack of electric guitar.

With the psychic damage already done, the transition into the six-minute devastation-epic "Shadow Valley" is perfectly seamless. Guitars continue to squall, moaning atmospheric textures choke out the possibility of sunlight, and Raposa finds himself at the end of his tether. "As long as I've lived / I wanted to die," he confides. "As long as I've loved you, I've been saying goodbye."

After revisits of squelchy madness on "High Plain 2" and desolation with "Refuge 2," City of Refuge ends with the complicated beauty of "After the Fall," an engrossing attempt by Raposa to make sense of how we come to terms with tragedy or disappointment. Delivered in a decades-defying croak, he begins with the tale of Adam and Eve being cast out of Eden as a jumping-off point for chronicling a litany of life's letdowns: friends and loved ones growing apart, emotional dislocation setting in.

A simple acoustic guitar pluck echoes carefully, sobbingly; in the distance, traces of piano quiver and swell against the echo in Raposa's weather-beaten ramble. Surveying all of the emotional damage done over the years, he lets loose of more than a few devastating couplets, but for me the true kick in the gut sets in with the where'd-everybody-go declaration, "now you can't go home again / we all moved after the fall."

It's the downside to remaining terrified of staying stuck in place, to be sure, and ultimately I'm finding it hard to shake the feeling that the desolation of Raposa's characters has nothing to do with geography at all. As the old cliché goes, "wherever you go, there you are" - and I'm beginning to think that the desert of City of Refuge might be just as much emotional as it is physical. It's an engrossing, challenging listen - and worth every itchy second.

CASTANETS
Fri/14, 9 p.m., $12
Hotel Utah
500 Fourth St., SF
(415) 546-6300
www.thehotelutahsaloon.com