Mercury – Act 1 is the fifth studio album by American pop rock band Imagine Dragons, released on September 3, 2021 by Kidinakorner and Interscope Records. Stylistically, Mercury – Act 1 contains elements of alternative rock, synth-pop, electropop, and R&B. Frontman Dan Reynolds described the album as split into two sides: one organic and looking inward, the other more aggressive and looking outward. The album’s name is derived from the word “mercurial”, drawing on Reynolds’ mental health struggles and the band’s lack of specific genre classification. The album touches on themes of loss, loneliness, and grief, while celebrating life. The band enlisted Rick Rubin as the album’s executive producer, whom Reynolds credited with pushing him to be less metaphorical lyrically and embrace the more “uncomfortable” aspects of songs.