At the core of Systems’ brilliance, at least on the Carrboro band’s debut, is the band’s ability to navigate the uneven line between thrash and post-rock. Here, these two disparate styles cooperate within a churning, nuanced soundscape, where thrash elements take on a cinematic, lonesome beauty. Post-rock has rarely sounded so rightfully oppressive.

As such, Ghost Medicine is one complex document, an anxiety-inducing and supremely dark album about the inevitability and totality of death. In these 41 minutes, brief periods of soaring triumph only make the general state of cathartic terror that much heavier. It all starts gently enough, with an ambient invocation familiar to fans of Mono or Explosions in the Sky. The band subverts the slow-blooming form by replacing familiar, euphoric post-rock tones with nervy, diminished chords. “Now our ship will sink,” Cameron Zarrabzadeh rasps in a shriek that approximates black metal. Subsequently, the record gets obsessively heavy and mean.

“For Ian Creath and Drew Wallace/ continued dosing/ of one sacred root,” Zarrabzadeh screams as the music hits its turbulent crescendo during “Datura Hallowing.” “Until I’m through/ coughing up and learning/ from their ghosts.” Both Ghost Medicine and Datura Hallowing are names for southwestern plants: the former is used in native medicine to help deal with loss, while the latter is a dangerous natural hallucinogen. Through this lens, the opening chant of “datura/ datura” takes on new menace and meaning, as if the fatal drug itself is calling its new victim.

Systems carry this dark catharsis to the end. Closer “Unveiled by the Fall” approaches epic release and perhaps redemptive resolution. A Red Sparowes-style progression marches toward an implied conclusion, but it’s repeatedly interrupted by guttural screams and bass-heavy, math-metal churn. Midway through one of these parts, the song and album simply stop. For a record about death and grief, it’s a fitting, devastating end.