It’s been more than two years since France’s Chaos Echoes released their debut full length album, “Transient,” which showcased the band’s deft navigation among labyrinthine channels under, around, and through the outer reaches of the extreme metal genre. “Transient” established Chaos Echoes as one of the most compelling and innovative groups of musicians in the scene. While this cassette is intended as a bridge between the band’s first and second albums, it is also an outlier of sorts, in that this recording is more shapeless and ambient than the album material. “The Unfathomable” is one track—the longest piece in the Chaos Echoes catalog—covering a full side of an LP. “The Unfathomable” is among the most evocative and atmospheric pieces Chaos Echoes has performed. It is desolate, ritualistic, and cold—lunar in its emptiness. It is a hymn to solitude, a collision of intermittent percussion, strings, and electronics, unfolding in slow, churning motions and abandoned to the corrosive machinations of entropy.