It's been months since Thor has been seen. Meanwhile, the group The Defenders have emerged, exhibiting real powers they've never had. This is Son of Satan, Power Man, Black Knight, Hellcat and Nighthawk. In the opening scene they have a confrontation with Iron Man and Hawkeye, until the Ultimates show up. However, they end up taking Mjolnir, which is the only way to rescue Thor. You see, the God of Thunder is in Valhalla, the Norse Land of the Dead, having to fight endless battles for Hela, Mistress of the Damned. She says she'll let him go if he'll give her a son. Meanwhile, we learn that his half-brother, Loki, is responsible for giving the Defenders real abilities. Among them is Valkyrie, Thors' girlfriend on Earth.
On Earth, we're introduced to the alternate world versions of Kazar and Shanna, which the media calls Sha-Zar. They end up fighting a dragon and some trolls alongside The Black Panther. Tony Stark (Iron Man) is having a relationship with Carol Danvers, who is in charge of Shield. She's influenced by Loki, and with Valkyrie and the incredibly strong Varda, manage to defeat the male members of the Ultimates while New York City is invaded by Loki's army.
Hela honors her agreement, and now pregnant, allows Thor to return to the land of the living, where he's pissed and attacks his fellow team members. Iron Man tries to reason with him--only there's a battle between the two instead. Will Thor see reason and come to his senses? Or is this another dire turn in the Ultimate Universe?
This book fits with all the major recent upheavals in the Ultimate Universe, which I'm sure will have some interesting consequences. Recommended.