"Return" by Hyolyn is a song about longing for a lost love. The lyrics describe the speaker's frustration with the emptiness of their current life without their lover, and their desire to be reunited with them. The chorus is a plea for the lover to come back to them, as they are "locked inside [the speaker's] heart" and the only thing that can bring them happiness is to be together again. The song also touches on themes of obsession and madness, with the line "Michin urisai jinjja byeolla like a psycho" (translated as "our crazy love is truly shining like a psycho"). This could be interpreted as the speaker being willing to do anything, even become obsessed or unbalanced, in order to be with their lover again. Overall, "Return" is a heartfelt ballad that explores the pain and desperation of losing someone you love.