When North Carolina's Jenks Miller began his Horseback project in 2007, he did so in absolute obscurity. Many of his recordings were done completely solo, issued either as split releases with other artists or as extremely limited-edition CD-Rs, vinyl singles, or tapes. But the quality of the work spoke for itself; word quickly spread through global subterranean music circles, and gradually bubbled to the fringe surface of mass culture itself. While Horseback's music is often classified as experimental black metal, that's a lazy catch-all. Black metal is a touchstone and an inspiration, but what's here is more mercurial, elliptical, and labyrinthine; it embraces, integrates, and obliterates other genres in its path. The Plague of Knowing is a mammoth triple-disc, three-hour-plus retrospective that, when taken as a whole, reveals the sprawling yet truly individual musical and sonic worlds that belong to Horseback. Disc one compiles singles, rarities, and Miller's contributions to split releases such as "A Heathen Earth" that appeared on a four-way cassette from Hand Made Birds in 2012, or the highly sought after "The Cult of Henry Flynt," from the 7" split with the Pyramids, A Throne Without a King. The closing track on disc one is an unreleased live version of the Stooges "T.V. Eye," with Miller and three other musicians assaulting it in extremis. Disc two is entirely comprised of the completely conceptual, cross-pollinated Stolen Fire cassette from 2012; but it's expanded here with five unreleased tracks, a demo, and an alternate version of "Do You Have a True Feeling?" While the previous two discs offer a treasure trove for those who missed them the first time as well as new material for the understandably obsessed, disc three is the true jewel here. It contains a reissue of 2007's long out of print Impale Golden Live, originally released by Holidays for Quince, on which Miller, a rhythm section, and two laptop players performed a dense, sonic dronefest. Also included is the previously unreleased, 44-minute title track, an unrelenting, seemingly endless repetitive assault with layered, distorted guitar that wafts, drones, and pulses with a serpentine lead line threading it together, amid rolling drum loops, and a single-note bassline that is almost unbearable in its blackened glory. A Plague of Knowing is both a welcome, vital document for fans and an exhaustive yet necessary introduction to one of the more provocative musicians of this era. To paraphrase the title of an album by the great acoustic guitarist Norman Blake, Horseback makes extreme underground music from the mysterious South; this compilation is the indisputable proof.