Lyric discussion by ooo_wee_ooo 

Cover art for Catacombs lyrics by At the Drive-In

i think this song is about the death grip of commitment. the "excavation" is talking about trying to renew the initial romance of the relationship, and "we're already dead" is talking about the relationship being dead. the bond, commitment, "gravity" is paralyzing him, and the rest is pretty easy to relate to that.