O'Brother intricate post-rock unfurls slowly and ominously as they attempt a mighty task here: coming to terms with infinity and contemplating the end of existence as we know it. Both terrifying and liberating, the theme fuels foreboding drums on "Slow Sin" and blustery guitar attacks on "Complicated End Times" and "Burn"—both of which mirror Muse's falsetto-tinged, apocalyptic rock. "Realm of the Physical" combines all of these elements into an exquisitely doomy closer of symphonic proportions, fading into hypnotic drones that sound beamed in from another world.