Once every 5,000 years, an event called the Convergence occurs, in which all of the nine realms are briefly lines up in a row. That event is happening...now. Malekith the Accursed, the leader of the Dark Elves from the realm of Svartalfheim, has been awaiting for this moment for quite sometime as he wishes to bring darkness to all of the nine realms. His ultimate goal is to plunge all of the Nine Realms into utter darkness and rule over them all.
Dark Elves begin to invade London. Meanwhile, no help can be expected from Asgard as they have their own Dark Elf issues, as well as their Bifrost Bridge is now destroyed.