"For Reasons Unknown" is a song by American rock band The Killers and was written by lead vocalist Brandon Flowers. It is the fifth track on their second studio album Sam's Town, released in October 2006. The song was released as the fourth single from the album in the United Kingdom on June 25, 2007, and also the fourth and final North American single.When the song is played live, bassist Mark Stoermer plays guitar on this track, with Flowers playing the bass.