Unlike some synth-pop revivalists, Crystal Castles have no default setting. For every track as sweet as “Suffocation,” with its sparkly electro-disco bass and cotton-candy vocoder, there's another as harsh as “Fainting Spells,” which runs Alice Glass' shrieks through fingernails-on-a-chalkboard distortion. And on songs like “Plague,” their ‘80s influences give way to icy trance synths and pummelling trap beats.