Written during the hunger strikes in Belfast, "Invisible Sun" was inspired by the idea that even in the darkest times, there must be a source of light that sustains hope. The lyrics explore how people in war-torn or impoverished countries find the will to carry on, conveying an uplifting and optimistic message despite its dark music and lyrical statements. It was a deeply personal song for the band's drummer, whose hometown of Beirut was being heavily bombed at the time of its recording. This song, from the album Ghost in the Machine, carries a powerful message of enduring hope.