The remoteness of the Knife (aka Olof and Karin Dreijer) and the chilliness of their music makes it easy to conjure up images of the duo working in a studio that resembles the Fortress of Solitude, playing instruments carved out of ice. But if the vibrant pop of Deep Cuts was like the northern lights, then Silent Shout is a sunless, vast expanse of tundra. A much darker, more ambitious set of songs than the Knife's previous work, the album finds the Dreijers stretching their sonics and downplaying the overt poppiness of Deep Cuts and The Knife. But, while Silent Shout isn't as whimsical or immediate as the Knife has been in the past, it's just as inventive, if not more so. Karin Dreijer's vocals are more striking than ever; treated as another instrument in the arrangements, they're layered, pitch-shifted, and tweaked until there's almost nothing left but tones and emotions. Her tweaked whispers on "Silent Shout" add to the song's pulsing, restrained, but very real menace; on "Na Na Na," she sounds like an alien diva. Likewise, Karin's whimsical, detailed lyrics also have a darker cast, offering glimpses of strange people in stranger situations. "From Off to On" deals with voyeurism and TV addicts; on "Like a Pen," Dreijer describes a character's struggle with body issues with disturbing clarity: "Sharpen my body like a pen...something too small for a lens." Many of the album's songs -- especially "Forest Families," "The Captain," and "Still Light" -- have a hushed, eerie intensity, but Silent Shout also sets off flares of emotion against its frosty backdrops. The fantastic single "We Share Our Mother's Health" is sleek yet chaotic, with marauding vocals set against frantic synths and beats that sound like the aural equivalent of blood bouncing on ice. The equally fantastic but completely different-sounding "Marble House" -- which was inspired by the classic French film The Umbrellas of Chebourg -- embodies doomed romance with its gliding melody and brittle castanet rhythms. The Knife eventually shows off its more playful side with the lumbering, cartoonishly macho "One Hit," which gives the album's sinister bent a mischievous twist. Truly unique -- even for a group as different as this one is -- Silent Shout is the Knife's most compelling work yet.