The song title refers to the volcano that laid waste to the Roman cities of Pompeii and Herculaneum in AD 79. The track is filled with metaphors of pagan and religious origin as Stevens calls on the volcano, the "fire of fire," to "fall on me now as I favor the ghost." Many of Stevens' songs have spiritual allusions and the Detroit born singer-songwriter consistently uses the word "ghost" to refer to the Holy Spirit in his music. On this track it appears he is using Vesuvius as a symbol for the ultimate fire, which is God, so it can be interpreted that he is singing about the Christian's lifetime struggle of choosing to following the Spirit of God which resides inside, or giving in to the desires of the flesh, which leads to death.
Stevens said of this song in concert at the Chicago Theater on October 15, 2010: "Standing at the edge of a volcano, pondering death isn't a very healthy way to live."