In their ongoing In the Fishtank series, the good people at Konkurrent have once again brought together two unlikely bands for a collaborative recording. In one corner, we have Boston, Massachusetts, prog-metal legends Isis. In the other we have Glaswegian post-rockers Aereogramme. The resulting EP does actually find a middle ground between the two groups, providing a half hour of startling beauty coupled with moments of untempered aggression. The disc starts with the nine-minute “Low Tide”. Featuring a much more blended mix of the bands’ styles that the rest of the disc, the track moves from fragile, emotive post-rock to driven, powered Krautrock. True to both bands’ styles, the track adds layers and volume to almost surreal heights, until the drums almost sound like they are being played on the roof of the studio. “Delial” follows, and is clearly an Isis song with Aereogramme adding texture around the edges. Following Isis’s template to perfection, interlocking drums and bass create a massive wall of sound as the vocals are buried, straining to get out. The chorus explodes and you can practically smell the sweat and see the veins bulging. Aereogramme add just enough of their knob twiddling to keep things interesting without defusing the song’s power. But it’s the closer “Stolen” that is most surprising. Running over ten minutes and built on ethereal, barely there guitar lines and airy vocals, the track slowly ascends to a Sigur Ros-like hymnal. But both bands refuse to get soggy here, and as the track winds down in its final minutes, it never offers the payoff you might expect, instead continuing to swirl until it disappears altogether from your stereo.