This song relates because Lena was extremely close to Macon, her uncle and when he died, she broke down and blamed herself because Macon gave his life to save Ethan when Sarafine killed him in the first book. As Lena is traveling through the tunnel with John, a new friend who says he can take her to a place where light or dark doesn't matter, she explains to John the way she feels about Macon. I cant help but imagine that if Lena were going to say something to Macon, it would be this song. This is an accurate description of how Lena feels from my perspective.