Unholy Passion is a 1985 EP by Samhain, the band's second release. The song "All Hell" is a re-recorded version of the Misfits' "All Hell Breaks Loose." It was released on 12" vinyl only, with either a tan or a maroon cover, on lead singer Glenn Danzig's independent record label, Plan 9.
The original, unaltered version of the EP has never been officially or legally released on CD, although its contents were added to a 1986 reissue of the Initium audio cassette. Since its initial release, the EP's tracks have been overdubbed (partially re-recorded) and/or remixed and included on various other Samhain releases, most notably the first pressing of the 'Initium' CD, and later, on the original 1990 CD and cassette releases of Final Descent. All releases of the remixed version of the EP contain the extra track "Misery Tomb".
On the re-issue, Glenn Danzig plays all guitars.