“De Selby (Part 1)” is the opening act on Hozier’s third studio album, Unreal Unearth, Taking inspiration from De Selby, an eccentric fictional philosopher, and scientist featured in Flann O'Brien’s novel The Third Policeman, Hozier explores the darkness in the context of connection; to self, to other, and to a sense of time and space, as explained in the track’s behind the song video. The track is special, in that it ends with Hozier singing in Irish.

The track was first teased back in January 2022, with a post on his socials and made its live debut together with its sequel, “De Selby (Part 2)”, in Gardone Riviera, Italy at Anfiteatro del Vittoriale