

Thomas Gabriel Warrior – vocals, guitars, synthesizers, effects.The cover image is a detail from the right ( Hell) panel of The Garden of Earthly Delights, a triptych painted in 1504 by Hieronymus Bosch, now part of the permanent collection at the Prado in Madrid. A registration of this performance has been released. Thomas Gabriel Fischer has performed the whole piece, with the long missing second part ("Grave Eternal"), at Roadburn 2019 with Triptykon along with the Metropole Orkest. The second part of the requiem was never released by the band. The track "Rex Irae" is the opening part of Celtic Frost's requiem the third, concluding part of which, "Winter (Requiem, Chapter Three: Finale)" can be heard on 2006's Monotheist. The lyrics to "Sorrows of the Moon" are an English translation of the same. For example, significant portions of Inner Sanctum are directly quoted from Emily Brontë poems, while the lyrics to "Tristesses de la lune" are borrowed from the poem of the same name in Charles Baudelaire's Les Fleurs du mal. Some of the lyrics are silently borrowed from other sources.

One in Their Pride, an industrial-oriented track, is built around various Apollo samples. The album has a more classic heavy metal style within the songs with elements of industrial, classical, gothic rock and doom metal. However, it does have the recurring symphonic elements found on previous albums. The album is vastly different from the band's previous work which cemented its late 1980s avant-garde metal term it is also a departure from the style found on the band's previous albums, Morbid Tales and To Mega Therion that Celtic Frost had become known for. The album is more varied than Celtic Frost's past LPs, with unlikely covers ( Wall of Voodoo's " Mexican Radio"), emotionally charged love songs, the album's recurring industrial-influenced rhythmic songs of demons and destruction, traditional Frost-styled songs about dreams and fear, and a dark, classical piece with female vocals. The album marks the return of bassist and backing vocalist Martin Eric Ain, who appeared on 1984's Morbid Tales, but not the band's previous album. Into the Pandemonium is the third studio album by Swiss extreme metal band Celtic Frost, released in 1987.
