Ragnarök is a Norse myth that tells of the 'final destiny', 'fate', or 'doom' of the gods and of the end of the earth itself. It foretells three long winters, the earth plunged into darkness and beset by earthquakes, a great battle involving the gods, and finally the covering of the earth with water, extinguishing life. The earth will then re-emerge, fertile and idyllic, to be repopulated by just two remaining humans (Líf and Lífþrasir). The gods will also return or be reborn. The written source material for the Ragnarök story comes from the Poetic Edda and the Prose Edda.

Full tellings of the rather beautiful Ragnarök myth can be found here and here.