Of late, Beck Hansen, reconstructionist of American pop, has been turning inward. His magisterial “Sea Change” was decidedly introspective and sad, and while his long-awaited “Guero” purportedly marks a return to his trademark junkyard-pop of “Odelay” fame, an undeniable loneliness, even darkness, lies beneath the new album.

Desert images pervade “Guero.” Here Hansen finds himself lost, angry and brooding, but mainly strange and delusional from the hot sun. But his quintessentially nonsensical lyrics somehow converge to make some kind of sense, painting mirage-scapes and apocalyptic scenes that underline an occasional religious tone.

Among other things, “Guero” is a self-referential album, drawing on bits from Hansen’s entire oeuvre. “Earth Quake Weather,” for example, shares the sultry funk beats of 1999’s Prince-like “Midnight Vultures,” while “Missing” — one of the most compelling songs on the album — borrows the thick string arrangements of 2002’s “Sea Change.” But embedded in all of these sounds is the unifying darkness of the lyrics that go with them. Thematically, this album’s lyricism goes well beyond the gloominess of “Sea Change” or the weird sexual intrigue of “Vultures,” but since most of its songs are upbeat in tempo and musical affect, the disparity is amazingly subtle.

“Missing” plays a tropicalia beat against its string section. Beck stumbles through the desert in search of a woman who won’t leave his head. The Arabian strings situate us, but the Brazilian guitar makes us question the setting — both make it clear that the sun is pounding. “I can’t see her hallow eyes,” Beck sings in an almost inappropriately chipper tone. “I can’t believe these tears were mine.”

“Weather,” with its strange, synthetic beat, continues the trek through the desert while Beck sings in a David Bowie-like incantation. The extremely catchy chorus masks the lyrics: “I push I pull, the days go slow/ Into a void we filled with death/ And noise that laughs falls off their maps/ All cured of pain and doubts in your little brain.”

“Girl,” with its acoustic guitar and video-game noises, is the catchiest song anyone could write with a chorus that affirms: “I know I’m gonna make her die/ take her where her soul belongs/ My sinner girl.” Beck sounds like a pop singer, layering “ahhs” on top of each other to sound lush and safe. The word “sinner” is left out of the liner notes, and Beck mumbles it so that it can almost be construed as “sunny.”

No matter how upbeat and party-like these songs are, nearly the whole album — with the exception of the title track, “Que Onda Guero” and the glitchy single “Hell Yes” — deals in some way with death, black dust, ghosts, angels or reapers. And not every track sounds like the “Odelay” party the album claims to be.

The immediately beautiful “Broken Drum” is a plaintive ballad that best captures the lyrical tone of the album as a whole. There is something spectral about this song; its pace is slow and its sounds are cavernous. Distant electric guitars accentuate an otherwise plain piano accompaniment. Smokey Hormel plays a brilliantly understated slide guitar riff, and Beck sings: “One by one, we’ll shoot our guns … your setting sun, your broken drum, your little drugs, I’ll never forget you.” The song fades out as the tortured electric guitars and piano disappear, echoing into distance.

“Farewell Ride,” at first a raunchy acoustic Delta blues number, sounds like nothing we ever hear in mainstream pop music. Beck howls in between harmonica riffs while background vocals hum and ahh — suddenly, we are in a spaghetti western scored by Ennio Morricone. Beck is again alone in the desert, literally being led to his burying ground, and he isn’t having a very good time.

The album’s final song seals the fact that it is no party album. The ominous beat of “Emergency Exit” is basically a hypnotic drone ornamented by humming and blips. Over the march-like music, Beck preaches: “What’s left of death is more than fear/ Let dust be dust and the good lord near/ It’s a little too much to ask of faith/ It’s a little to late to wait for fate.” And there’s more: “So tell the angels what you’ve seen/ Scarecrow shadow on a Nazarene.”

Dance all you will — after all, people grind to “Jesus Walks” — but “Guero” seems to be making a rather strong statement of faith. His apocalyptic preaching, teamed with the Dust Brothers’ glorious beats (also of “Odelay” fame), makes for perhaps the strangest album Beck has made to date, and it’s almost unnoticeable.