For the briefest of moments, it was possible alt-J had been moved to lyricism by the Berkeley road of the same name, but alas, it was not meant to be. According to the band, “Adeline” — written on-tour —  is set in Australia and chronicles a Tasmanian devil falling in love with a woman as he watches her swim.

If that doesn’t sound like a beautiful concept, alt-J might just convince you it is. Backed by a luscious string section recorded at Abbey Road Studios, the track swims through murky sonics. Singer Joe Newman’s vocals are often partially obscured, sitting deep in the mix, almost a textural instrument rather than a vehicle for lyrical ideas. The song feels, at moments, like you are hearing it from deep underwater — appropriate, not only for the swimming conceit but for the gulf of uncrossable distance between the song’s subject and the object of its affection.

“Adeline” is more than tinged with sadness — melancholy drives the track from its opening notes, the lyrics offering little hope of success in the romantic premise. In the opening verse, Newman sings “Down in Tasmania / where the devil’s jaws are far too weak / to tear you away.”

Far more in line with first release “3WW” than “In Cold Blood,” “Adeline” is a slow, patient build that doesn’t shy away from its emotional core. It’s marked by restraint; the buildups in the latter half of the nearly six-minute track culminate not in climactic explosions of joy but in quiet relinquishments. “Swim on,” Newman almost whispers, “I wish you well.”

It takes a few listens to really get it, to get over the distance of Newman’s vocals. He sings not as himself, but on behalf of another through an insurmountable barrier. But underneath the pensive lyrics, the opening, jungle-esque sounds give way to a driving heartbeat of drums around the two-minute mark that, while distant and muffled, carry the weight of the gorgeous orchestration resting above.

That orchestration is key to the slowly forming picture of alt-J’s upcoming album, Relaxer. The band’s first two albums, An Awesome Wave and This Is All Yours, are marked by forward, present, often syncopated drums and a sparse instrument set driven primarily by Newman’s guitar licks and Gus Unger-Hamilton’s keyboards. With Relaxer, alt-J seems to be augmenting its arrangements with the introduction of live horn and string sections into their mixes.

“Adeline” demands more of its listeners than “3WW,” and the end result is a song that reveals itself to be imbued with depth and beauty — and profound sadness — slowly, on each repeated listen. To a certain degree, the fact that it’s a Tasmanian devil who is hopelessly in love is a subversive choice; it abstracts the sadness of the piece away from the over-trodden veins of the traditional love song.

“Adeline” works because that heartache is characterized not by conventional unrequitedness but by an immediate, visceral understanding of an insurmountable difference.