In Norse mythology, Fimbulvinter (or Fimbulvetr) is the harsh winter that precedes the end of the world and puts an end to all life on Earth. Fimbulvinter is three successive winters without any intervening summer. During this time, there will be innumerable wars and ties of blood will no longer be respected. The title was inpired by Amon Amarth's "The arrival of Fimbul vinter" because, well, "Vigilant warrior and her two-headed dog" would be descriptive but rather boring. That, and the fact that Amon Amarth songs are awesome.