Book of Horizons is the fourth studio album by Secret Chiefs 3, released May 25, 2004.

"The Owl in Daylight" is inspired by the final, unfinished novel of the same name by renowned science fiction writer Philip K. Dick before his death.

The Allmusic review by William York stated "Secret Chiefs 3's first three studio albums were not exactly stripped-down affairs, but Book of Horizons is by far an ambitious release ... this is a frequently jaw-dropping album that should silence Spruance's anti-Bungle critics and, more importantly, challenge and entertain devoted fans of his past work".

[2] Daniel Lukes of Lollipop Magazine called the work "plaintive, harsh, witty, baffling, and thrillingly alien," saying "The overall effect is akin to the imaginary soundtrack to an uncanny, Burroughs-esque parallel universe where gumshoes mix with Arabian mystics, cowboys, and aliens in search for the Ultimate Truth."

Pitchfork contributor Jonathan Zwickel noted "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"[3] The Scene Point Blank review warned "If you have a short attention span you are probably going to get lost mid-way through Book of Horizons.