It's H.P. Lovecraft's birthday today. When I was a kid, I always saw Metallica as "Meathead Metal", but they are actually a very literate band. This song is based on Lovecraft's 1931 novella "The Shadow Over Innsmouth". Off the top of my head, Metallica has also done "Call of Ktulu" (apparently inspired by "Call of Cthulhu", also by Lovecraft), "For Whom The Bell Tolls" (inspired by the Hemmingway book of the same name) and "One" (inspired "Johnny Got His Gun" by Dalton Trumbo). Metal is actually a very well-read genre.