The first four minutes of this 11:29 song is a falsetto-laced pop number about a couple seeking closure who want to spend one last night together. However, then the track unfolds into an instrumental space-age jazz-rock jam featuring seven minutes of interplay between guitarist James Valentine and keyboardists P.J. Morton and Jess Carmichael. Valentine recalled to Artist Direct the session in the studio which produced the extended outro:
"There was one day when we were all there, we were jamming on the song 'Closure' and we just kept on jamming, and it ended up making the record as the last song on the record, and it ends with a pretty long jam session, and it was like, 'This would be a pretty good way to close the record because this song is also called "Closure"' That was a really fun day and that was all of us recording live together in the room. That also felt like old times and that was a real fun moment of the record."
New Order took the title for "Blue Monday" from an illustration, which read "Goodbye Blue Monday," in the Kurt Vonnegut book Breakfast Of Champions. The image referred to the invention of the washing machine improving housewives' lives.