When the macrocosm was dark, a race called the Dark Brownies ruled. Also came the Light, and they lost their power. Malekith, the sovereign of the Dark Brownies, wants to use the Aether ( Reality Gravestone) and throw the world back into darkness. Now, there's an event that aligns all the nine realms together formerly every 5000 times. It’s called Confluence. Malekith tries to use the Aether to darken the world in a former confluence but is stopped by Thor’s granddad. Hence Malekith puts himself and many other Dark Brownies in a state of hibernation. In the present day, as the coming confluence approaches, doors begin to aimlessly appear in the 9 realms.
Jane goes to probe one similar portal and gets smelled into the realm where the Aether has been kept hidden from Malekith. Jane activates the Aether by mistake, and it enters her. This awakens Malekith and the other hibernating Dark Brownies. The Aether begins to kill Jane because of its power. Long story short – Thor takes Jane to Asgard, Malekith attacks Asgard to get Jane, Thor’s mama dies guarding Jane, Loki joins forces with Thor to retaliate against his mama, Loki tricks Malekith by bringing Thor and Jane as his captures, Malekith excerpts the Aether from Jane, Loki dies (no he doesn’t, Loki is faking it again, he’ll be back in the end), Thor and Malekith fight through the colorful doors, Thor eventually kills Malekith. In the end, Loki is posing as Odin and ruling Asgard. The real Odin is on Earth, we’ll get to that in Ragnarok.
The Dark WorldPost-Credits Scene
We’re shown the Asgardians giving the Aether to a person called the Collector stating that it’s not a good idea to keep two Perpetuity Monuments so near to each other. The Asgardians are formerly holding the Tesseract (Space Stone) in their protection.