Two years after the Battle of Sokovia, Thor tried unsuccessfully to find the Stones of the Infinite, and is now imprisoned by the fire demon, Surtur. It reveals that Thor’s father, Odin, is no longer in Asgard, and the realm will be destroyed in the Ragnarok profession as soon as Surtur unites his crown with the Eternal Flame that burns under the city. Thor defeats Surtur and takes his crown, believing that once with this he prevented the fulfillment of the Ragnarok prophecy.
Thor returns to Asgard and finds Loki taking over Odin’s face. Thor obliges Loki to help him find their father and, with help from Stephen Strange on Earth, they locate him in Norway. Odin tells his sons that he is dying and that this will allow the firstborn, Hela, to escape from a prison where she was locked up a long time ago.
Hela was once the leader of Asgard’s army and conquered Nine Realms with Odin, but was imprisoned and removed from history after his ambitions became too great. As soon as Odin dies, Hela makes his appearance and destroys Thor’s hammer, and when Thor and Loki try to run through the Bifrost Bridge, she pursues them and takes them out of space to die. Hela arrives in Asgard, destroys the city’s armies, and brings back to life the dead who fought with her, including his giant wolf, Fenris.