Mogočni nebeški bojevnik Thor mora znova prijeti za svoje bojno kladivo in rešiti vesolje pred uničenjem.Starodavna nezemeljska rasa, ki jo vodi maščevalni Malekith, želi uničiti vseh devet svetov obstoja in vesolje oviti v večno temo obupa in kaosa. Ker se niti oče vseh bogov Odin ne more sam zoperstaviti tako veliki sili uničenja, mora Thor za pomoč zaprositi dvoličnega brata Lokija, toda za zmago bo moral neustrašni bojevnik žrtvovati tudi tisto, kar mu je najbolj pri srcu.
Thousands of years ago, a race of beings known as Dark Elves tried to send the universe into darkness by using a weapon known as the Aether. Warriors from Asgard stop them but their leader Malekith escapes to wait for another opportunity. The warriors find the Aether and since it cannot be destroyed, they try to hide it. In the present day, Jane Foster awaits the return of Thor although it has been two years since they last saw once another. In the meantime, Thor has been trying to bring peace to the nine realms. Jane discovers an anomaly similar to the one that brought Thor to Earth. She goes to investigate, finds a wormhole, and is sucked into it. Back on Asgard, Thor wishes to return to Earth but his father, Odin refuses to let him. Thor learns from Heimdall, who can see into all of the realms, that Jane disappeared. Thor then returns to Earth just as Jane reappears. However, when some policemen try to arrest her, an unknown energy repulses them. Thor then brings Jane to Asgard to find out what happened to her. When the energy is released again, they discover that when Jane disappeared, she crossed paths with the Aether and it entered her. Malekith, upon sensing that the time to strike is now, seeks out the Aether. He attacks Asgard and Thor's mother Frigga is killed protecting Jane. Odin wants to keep Jane on Asgard so that Malekith will come. Thor disagrees with his plan, so with his cohorts, he decides to take Jane away. He enlists the aid of his brother, Loki. Unfortunately, Loki's motivations remain unknown.