Presaged by Heimdall blowing the Giallar horn on the Bifrost Bridge, Yggdrasil, the world ash, is shaken from root to summit. Odin rides from Asgard to consult Mimer at the Well of Wisdom. Jormungandr, the Midgard serpent, rises from the depths and causes the seas to boil over and flood the world. The giant Hrym appears on the far horizon, sailing the ship Naglfar, the ship of nails. The Bifrost Bridge shatters. Garm, the guardian hell-dog of Helheim, breaks his bonds.
Odin leads the hosts of Asgard and his companions from Valhalla, the hall of the noble dead, onto the battlefield of Vigrid, against the assembled armies of giants, headed by Fenris, Garm, Jormungandr (the serpent of Midgard), and Loki, who at the last betrays his erstwhile comrades.
Odin is eaten by Fenris, who in turn is rent in twain by Vidar, the silent god. Heimdall and Loki kill each other. Thor kills the Midgard Serpent with his hammer, Mjollnir, but dies of its poison. Skoll the wolf consumes the sun and in the aftermath of the battle, the world is consumed by flames and sinks into the sea.
- Common Swedish form: Ragnarök