“Of course we’re growing restless,” wrote the Knife in the manifesto that accompanied their last album, Shaking the Habitual. They cited “hyper-capitalism,” Monsanto, ecology, privilege; they imagined the pulse of a throbbing dancefloor rearranging clubbers’ very DNA. It was a vision of music as catalyst: They had few answers, but they knew that something—everything—needed to change. “This time it’s structural,” they wrote, more presciently than anyone could have realized at the time. This bar graph could be your life.

If Shaking the Habitual feels like a long time ago now—four whole years!—then 2009’s Fever Ray feels like another era entirely. But then Karin Dreijer and her brother Olof have never put much stock in pop music’s three-minute jolts, despite the early success of singles like “Heartbeats.” For all the left turns of their respective careers, they seem less interested in following the calculated steps of the typical album cycle than in the long sweep of a far more unruly trajectory. They set their clocks not by the Grammys calendar, but something more naturally unfolding—moss time, maybe, or ice-melt time. Seven years passed between the Knife’s Silent Shout and Shaking the Habitual; eight years mark the gap between Fever Ray and Plunge. In that time, Fever Ray’s music and character have settled in with a deep familiarity in ways that the Knife’s constantly shape-shifting identity—with its stylistic detours, its costume changes, its forays into opera and Charles Darwin and queer theory—has not. The Knife keep you on your toes, but Fever Ray has always felt like a port in a storm.

From the beginning, Dreijer’s solo music has carried a supernatural charge: Her pitch-shifted voice and chiming parallel fifths are enough to make the hairs on your arm stand on end, as though you had been visited by a ghost. The idea of Fever Ray as a kind of transcendental mood music was reinforced by the use of “If I Had a Heart,” the opening song from Dreijer’s 2009 solo debut, in the opening titles of the History Channel series “Vikings.” If anything, the choice of the song felt like cheating: No matter how striking the visuals, they paled beneath the song’s powerful sway. More than merely atmospheric, Dreijer’s vivid sonics and imagistic lyrics tend to conjure entire worlds: Hit “play” and be instantly transported to a world of heavy skies, visiting magpies, velvet mites.

If the Knife’s evolution represents a gradual politicization, a shift from fantasy to praxis, the new Fever Ray is also political in a way Dreijer has not been before. She sings of “Free abortions/And clean water” on “This Country,” a grinding electro dirge at Plunge’s center; “Destroy nuclear/Destroy boring,” she cries, in one of those perfect couplets that go to the heart of her inimitably anarcho-Scandinavian perspective. (Fingers crossed that future Fever Ray merch includes T-shirts printed with those lyrics.) As she shrieks on “This Country,” “Every time we fuck we win/This house makes it hard to fuck/This country makes it hard to fuck!”

There is a fair amount of fucking on Plunge, which might come as a surprise. Where Fever Ray was largely about motherhood and the search for self—ideas she refracted through the lens of elemental forces, animism, images of fur and fire and snow—Plunge focuses all of its energies on love and desire, with a striking candor. Heads turned when, on the album’s early single “To the Moon and Back,” she shouted, “I want to run my fingers up your pussy!” When had Dreijer ever been this direct, this libidinous, this scandalous? And when, at least since “Heartbeats,” had she made anything that sounded quite as sweet or as perky, even cloying, as “To the Moon and Back”’s major-key arpeggios, Latin freestyle bassline, and delirious sing-song vocals?

But that song’s chipper tones turn out to have been a head-fake—an outlier in tone and mood on an album far noisier and more hot-blooded than Dreijer’s previous solo work. Plunge feels much more manic, more conflicted, than her debut. If Fever Ray was distinguished by its penumbral chill, this album puts the heat and light back into her alias: the fever, the radiance, the beams emanating from red-ringed eyes.

It’s not a total departure: Her electronic soundscapes are often soft and full of mystery, suggesting cobwebs glistening in the moonlight, and she has retained many hallmarks of her sound. She sends her synthesizer queasily pitching and reeling, and she favors synth patches that straddle the “real” and the artificial, like the wheezing pan pipes of “Mustn’t Hurry” or the faux vibraphones and woodpecker bursts of “To the Moon and Back.” Her ubiquitous perfect fifths, with their bold, unresolving tones, generate a kind of force field—a zone of life-giving vibration. It is hard not to feel invincible while Fever Ray is playing.

Which is good, because Plunge is riskier than anything she has made before. It is sometimes harsh, often dissonant, frequently audacious. Her voice no longer hides behind the pitch-shifting it once did; here it is sharpened and pushed high in the mix, the better to emphasize her strange, elastic, playful diction—vowels stretched and twisted in unpredictable ways, consonants that slice like paper cuts. Her voice throws off sparks as it comes into contact with similarly tempered sounds: the cascading rave stabs of “Wanna Sip,” Sara Parkman’s see-sawing violin in “Red Trail,” a scraped echo of John Cale’s viola in the Velvet Underground. “Falling” rides a beat crafted from dial tones, alarm bells, and patches of reverb as slick and hard as black ice. “IDK About You,” the album’s most thrilling song, hurtles ahead atop a 150-BPM beat of rolling toms and shrieking cuíca; Dreijer’s distorted vocals sound like she may have recorded them on her phone. The track is a collaboration with Nídia, a 20-year-old Portuguese batida producer, and it’s the song that ventures the furthest from Dreijer’s own moody wheelhouse.

The desire that fuels Plunge is shot through with danger, and although she never quite spells it out, the specter of societal taboo looms around the corner of every kiss. “That old feeling of shame/She makes me feel dirty again,” Dreijer bellows in “Falling.” She sings of toxic habits, of painting in blood, of “perverts.” Sometimes she sidles right up to violence, looks it in the eye, and stares it leeringly down: “Gotta love my tracks/And swing an axe,” she taunts a potential lover, practically daring them to swipe left. But elsewhere, the meanness of the world presses in. “A Part of Us” imagines planting a garden, building a family, but the idyll is shadowed by menace: “What we are/Brings the wrong kind of attention out here,” she warns, at once vulnerable and coiled, spoiling for a fight, “One hand in yours and one hand in a tight fist.”

Like Shaking the Habitual, Plunge is also accompanied by a manifesto of sorts. It is often cryptic. “Listen!” Dreijer writes, in collaboration with the British artist Hannah Black: “Sex is work, love is work, work is sex, work is love, the magical conversion of ‘is’ given impossible power by its delivery in music.” This is the language of someone projecting matters of the heart through critical theory—the language of someone grappling deeply with the implications of desire. Her meditations on the relationship between subject and object, song and lover, are as complicated as her tangled, tumultuous electronics, her drawn-out snarls. But the text also helps to spell out some things: “The decision to fall is harder than the fall itself,” she writes, underlining that the plunge in question is falling in love. Further on, she specifies, “I’m looking for a girl who stands 10 feet tall and has teeth like razors… I’m looking for a girl to affirm my reality, or cancel it.”

It is not until the album’s closing song, the enveloping “Mama’s Hand,” that she cuts to the heart of the matter. The cycling arpeggios suggest a slowed-down companion to the Knife’s “Forest Families”; the hopeful lyrics stretch backward and forward in time. The details are Dreijer’s to know and ours to guess; they concern family and motherhood and, perhaps, a new partner entering the fold. But it all ends on an unambiguous image: “The final puzzle piece/This little thing called love.” Plunge is not just a record about falling; it is more fundamentally about transformation. And here at the end of a profoundly, thrillingly restless album, she stakes out something like freedom.