Roxxon Seabase under the Norwegian Sea suddenly comes under attack from aquatic Frost Giants….
On the moon, Thor has been struggling for weeks, constantly trying to lift Mjolnir and always failing. His family and friends have gathered about him; Father Odin tries to bully him into standing up but he is ignored. Freyja has learned from Captain America that this is the result of something his enemy (Nick Fury) whispered to him; no one knows what it is and Thor will not reveal it. Neither Odin nor any other champion can lift the hammer either. Word comes that the Frost Giants have invaded Midgard; Thor heads to the Hall of Weapons to retrieve his ax Jarnborn, the weapon he carried before he was found worthy of Mjolnir and then goes to Earth….
The Dark Elf King Malekith magically appears in the seabase and informs the surviving explorers that they have something the Frost Giants want—and he kills each human who doesn’t know what he means…. Thor crashes into the lab and there ensues a furious battle between hero and villain, as the room fills with water. Malekith’s taunting distracts Thor long enough for the giants to seize him—and the Dark Elf uses Thor’s own ax to chop off his left arm. The villain takes what he came for and departs, thinking he has seen the last of Thor….
On the moon a female figure approaches Mjolnir and lifts it. The inscription now reads "If she be worthy…." She raises the hammer and there stands revealed the new Thor….