The two experimental legends first collaborated on 2018's 'Nordlicht', a heady collection of subs and drone experiments that harked back to Roedelius's earliest material. 'II' is a continuation of those ideas, focusing the duo's energy on three richly-textured movements that advance its predecessor's tenebrous drones into even foggier spaces.

'Zwei Herzen Träumen' (two hearts dream) is the briefest track and also the album's most cybernetic, launching us into its foreboding atmosphere without completely drowning us in darkness. It's here where there are the most obvious echoes of Kluster, Roedelius's dazzlingly experimental pre-Cluster formation, but where the kosmische pioneers used an arsenal of instruments, Roedelius and Hausswolff keep things much more concentrated, using sculpted oscillators to suggest a similar mood.

'Under the Ocean' is where things start to get more screwy, beginning with a subterranean rumble that sounds as if it's been captured under the earth's crust. The movement of the piece comes from tiny generator fluctuations that cause resonant wobbles that ripple through the track, like waves generated by a stone being tossed into a lake. The duo's rumbling tones are hypnotic, a disquieting combination of whooshes and ominous howls.

On the 17-minute closer 'Ossuaire’, the duo lean into their most gothic inclinations, futzing with endlessly cascading bass drones that sit somewhere between Sunn O))) and Kevin Drumm, unspooling slowly and warbling into the void, picking up faint, wordless radio communications from the aether.