Thor: Ragnarok (2017)

Asgardian Thor Odinson (Chris Hemsworth), God of Thunder, battles the fire demon Surtur in a hellish world. Surtur's goal is to cause Ragnarok, the destruction of Asgard. Thor defeats Surtur and takes his crown back to Asgard. Thor discovers that his evil brother Loki Laufeyson/Odinson (Tom Hiddleston), God of Mischief, is still alive. Loki faked his death during a battle with the evil Malekith (Christopher Eccleston) and the Dark Elves, and has been ruling Asgard disguised as Odin (Anthony Hopkins). Loki banished Lady Sif (Jaimie Alexander) from Asgard, fearing she would expose him. Loki also denounced Bifrost Gatekeeper Heimdall (Idris Elba) as a traitor and replaced him with Skurge (Karl Urban), but Heimdall escaped before his trial. Loki takes Thor to Norway, where he banished Odin.

The dying Odin tells Thor and Loki that their evil sister Hela (Cate Blanchett), Goddess of Death, will be freed from her prison dimension once Odin is dead, and that her powers will be limitless once she reaches Asgard. Odin disappears and the freed Hela confronts her brothers. Thor hurls his hammer Mjolnir at Hela, but she destroys it with ease. Loki yells to Skurge to open the Bifrost portal. However, Hela enters the Bifrost and knocks Thor and Loki out of it and into space. Arriving on Asgard, Hela kills the Warriors Three and Odin's army, and recruits Skurge as her servant and executioner. Meanwhile, Thor lands on Sakaar, where he is captured by Valkyrie (Tessa Thompson) and brought to the villainous Grandmaster (Jeff Goldblum), ruler of Sakaar and creator of the Contest of Champions. Loki had actually landed on Sakaar weeks before Thor and is now part of the Grandmaster's favorite elite because of Loki's own selfish, villainous nature. Despite revealing he is Thor's adopted brother, Loki does nothing to help Thor escape.

The Grandmaster forces Thor (with an obedience disc attached to him) to battle his favorite champion, the missing Hulk/Bruce Banner (Mark Ruffalo). Thor almost defeats Hulk, but Grandmaster uses a remote to activate Thor's obedience disc which zaps Thor, allowing Hulk to defeat Thor. Back on Asgard, Hela reveals to Skurge that she was Odin's executioner years ago and that they had conquered many realms to build Asgard's empire. Odin later renounced his evil ways and turned good, during which time he banished Hela and raised Thor with his late queen Frigga (Rene Russo). Odin even made peace with Laufey (Colm Feore), king of the Frost Giants of Jotunheim and Loki's biological father. Loki killed Laufey and several Frost Giants in the first film. Odin covered his ceiling art depicting himself and Hela killing and conquering with new ceiling art depicting himself, Frigga, Thor, Loki, Laufey, and the Asgardians at peace. Hela destroys the peaceful art, revealing the old art showing her evil deeds with Odin underneath. In Odin's vault, Hela uses the eternal flame to resurrect her dead army and her giant wolf Fenris.

Heimdall has retaken the Bifrost sword and has been leading Asgardians to a safe haven. Back on Sakaar, Thor and Hulk (who has turned back into Banner) escape Grandmaster's headquarters, angering Grandmaster. To avoid being executed by Grandmaster, Loki and Valkyrie offer to bring Thor and Hulk back. However, Valkyrie captures Loki and decides to help Thor and Banner go to Asgard and defeat Hela. Loki offers to help Thor steal the Grandmaster's favorite spaceship, but attempts to betray Thor again. Thor leaves Loki behind and he, Banner, and Valkyrie battle Grandmaster's minions before escaping to Asgard. Gladiators led by Korg and Miek find Loki and offer him a flight on the spaceship they're going to escape on. Loki decides to lead them and they head to Asgard. Meanwhile, Thor battles Hela inside the palace, while Heimdall and the other Asgardians battle Skurge, Fenris, and Hela's minions on the Bifrost bridge. Hela blinds Thor in one eye. Loki, Korg, Miek, and the other gladiators arrive and join the battle against Hela's minions. Hulk battles Fenris, who falls over the waterfall into space.

After hitting Hela with a lightning blast, Thor realises the only way to stop Hela for good is to cause Ragnarok. While the Asgardians (including Skurge) board the ship, Loki gets Surtur's crown from the vault and places it in the eternal flame. When Hela's minions board the ship, Skurge sacrifices himself to kill them. Skurge jumps back onto the Bifrost bridge and kills the remaining minions, but Hela kills Skurge. Then the reborn Surtur grows giant and destroys Hela by plunging his fire sword through her and Asgard, killing himself as well. On the spaceship, Thor is crowned king of Asgard and talks with Loki about returning to Earth. Suddenly, a huge spaceship belonging to Loki's old ally, the villain Thanos, appears in front of them. Thanos has presumably come for the Tesseract which Loki (who still has his own agenda) took from the vault before Asgard's destruction. In a post-credits scene on Sakaar, the creatures who rebelled against the Grandmaster surround him. Grandmaster declares the revolution a tie.