Back when the self-titled sophomore album came out, I can remember a Spin article about how Portishead producer Geoff Barrow couldn't find any old spy-movie soundtrack-music that he wanted to sample anymore, so he wrote and recorded his own, never releasing it, just so he'd have something to sample. That's a depth of obsessive perfectionism that not too many can equal, and it's not too hard to imagine that Barrow's spent the past decade tinkering with keyboard sounds, inventing his own vintage synths because none of the ones he could find evoked all-consuming dystopian dread perfectly enough. Dread is what always separated Portishead from their lame-ass trip-hop peers, and that sense of foreboding remains thankfully fully intact on the new one. Those drizzly snares and tremolo guitars that Barrow once pillaged don't work the same way anymore, so he's found himself a new slate of sounds. Trip-hop was always a ridiculous name for a genre, but Barrow's dusty breakbeats and Premier-esque scratching at least nodded toward what was going on in rap at the time. They're gone now. We get a few huge, clomping, fuzzed-out electro beats over the course of Third, but we're not exactly talking about repurposed "I Get Money" here. If the album recalls anyone other than Portishead, it might actually be Led Zeppelin: monolithic textures, vague hints of Middle Eastern melody and pastoral folk, slow builds to miasmic psyche-rock climaxes. That's a completely inexact analogy, but it's hard to find any exact way to talk about a record this diffuse in exact terms.

It's pretty ballsy for them to call the first song on their post-hiatus album "Silence," but it's even ballsier for a group famous for makeout music to give that song a jittery falling-over-itself krautrock beat that never settles into a comfortable groove. Gibbons's voice doesn't appear until two minutes into the song, and then it sounds like she's singing from the bottom of a well with no hope of ever being able to climb out; she's faraway and dead inside. It's so not a sex-jam. Gibbons's voice is somehow simultaneously earthly and ghostly, and throughout Third, Barrow treats her voice to sound like it's coming through bad phone lines or crackly old 78s. It's just one element in the mix, and sometimes you have to strain to hear it. The lyrics, as ever, are nothing special: "I can't deny what I've become / I'm just emotionally undone," that kind of thing. But it's fascinating hearing Gibbons work. Barrow never allows her the space to float over tracks the way she once did. Instead, she has to fight for room on clanking, unforgiving tracks. Noise plays a big part on this album, but Barrow works the noise in subtly. On "Plastic," weird and disquieting helicopter noises fade in and out. "We Carry On" has scraping postpunk guitars and car-horn blats. "Machine Gun" sounds almost like screwed-up industrial; for most of the song, the only thing we hear besides Gibbons is a martial electronic drum-thwack. But noise doesn't derail the songs. Instead, Barrow uses it as a tool. The tension in the tracks builds and subsides expertly, but it never quite finds release. This is bleak, suffocating, almost unbearably sad music, and you'd have to be truly disturbed to fuck to it, which means a lot of people probably will.

The leak that's floating around doesn't sound finished; tracks cut off early and sound-levels change. But if the final product is as dense and powerful as what I'm now hearing, I'll just have to forget that Morcheeba ever existed.