Depeche Mode's music returns again and again to the subject of inner struggle. “Clean” is a bittersweet ode to sobriety pierced by synths as sharp as the light of day, while Dave Gahan's “Dirty Sticky Floors” wraps an addict's desperation in grimy beats and oozing slide guitar. Although “Dangerous” is a darkly alluring look at feral desire, the stark “Death's Door” offers a rare glimpse of salvation.