"...an outside-the-box journey into sights and sounds from far and deep into the imagination, and a fascinating antidote to the often stultifying dearth of vision and ambition in so much rock music today."

Daniel Lukes, Lollipop
  

"...Secret Chiefs 3 have existed in various incarnations over the course of the past eight years, and have served as the funnel for Spruance's remarkably far-flung studies of the hermetic mysteries and musical traditions of unknown and underappreciated subgenres. Album titles like Grand Constitution and Bylaws and Book M hint at the music's vaguely metaphysical bent. Over three years in the making, Book of Horizons is Secret Chiefs' most expansive and coherent statement, an alchemical fusion of Morricone-esque cinematic grandeur, midnight surf guitar, traditional Middle Eastern rhythms and time signatures, demonic death metal, and electronic deviance that yields a work of undeniable force."

Jonathan Zwickel, Pitchfork
 

"Cast the clear light of alchemical truth through the graphically enhanced occult fog, and you'll find an album fluffed full of magick, mystery, and densely orchestrated mosque-rocking beats."