Probably THE most important Lovecraftian extreme metal band. If you like your Death metal a bit blackened, with a dollop of Behemoth sauce, served on a dark, dank, diluvial bun, this is your album.
A definite "listen to from start to finish on good headphones" album. Read along with the lyrics (google) the first couple of times. Some song lyrics almost tell continuing stories; this is a loose concept album.
Bonus: Probably the best cover art, in any genre.