in 1988, queensrÿche released "", a narrative concept album that proved a massive critical and commercial success. the album's story revolved around a junkie named nikki, who is brainwashed into performing assassinations for an underground movement. nikki is torn over his misplaced loyalty to the cause and his love for mary, a reformed hooker-turned-nun (vocals by pamela moore), who gets in the way. the band's progressive metal style was fully developed on this album. the band toured through much of 1988 and 1989 with several bands, including def leppard, guns n' roses and metallica. the album gained critical acclaim and achieved gold status.