This minor-key acoustic folk ballad is about a soldier dying in the snow of Afghanistan, focusing on his last thoughts. Like a number of tracks on No Line on The Horizon, this was written by Bono about a specific character. He explained to The Observer Music Monthly February 2009: "I just got tired of the first-person so I invented all these characters; a traffic cop, a junkie, a soldier serving in Afghanistan."
The musical arrangement is based loosely on the ancient Christmas carol, "O Come, O Come, Emmanuel" which has previously been covered by a number of artists, including Enya and Belle And Sebastian. Co-producer Daniel Lanois explained to The National Post why they borrowed from the hymn: "After my conversation with Bono about future hymns or future spirituals, I did a little studying. In fact, with a friend in Toronto, Lori Anna Reid - she's a great singer from Toronto and she's quite an expert on spirituals. I asked her to fish a few out for me and we had a listening session and that one stood out to me. It's an old church hymn called 'O Come, O Come Emmanuel.' It's not identical, but it's inspired by that, an old public domain melody. I laid down a little piano version of that song, again, chopped it to a tempo. Then I came up with a vocal arrangement. Bono had this 'white as snow; idea. It just slowly came together."
This features in the 2009 Jim Sheridan war film Brothers.
Bono came up with the idea of focusing on the soldier's last thoughts as he dies from his wounds after reading William Golding's 1956 novel Pincher Martin. The book tells the story of Christopher Hadley "Pincher" Martin, the sole survivor of a military torpedo destroyer which spontaneously sinks in the North Atlantic Ocean.