First up, it's the final part of the Tanarus story which spun out of Fear Itself. Since the story is a forgone conclusion(we've already seen Thor in several Avengers comic books!), there's no sense on wasting time doing a long intro, let's just get to business here.
Mighty Thor #12:
Summary: Thor manages to kill the god-eating Demogorge, which allows him to head back to Earth and Asgardia. Upon arriving, he sees Asgardia under siege by the trolls and the Norn Queen. Thor attacks Tanarus while Thor's mother, Freyja, takes on the Norn Queen. As the people of Asgardia see Thor, they regain their memories of him, destroying the Norn Queen and Tanarus/Ulik the Troll's enchantment. Thor apparently hits Ulik so hard with his hammer Ulik turns into a shiny skull(wha?!) and Freyja defeats the Norn Queen. With the main troublemakers dealt with, the troll legions quit the battle and Freyja locks the Norn Queen and the king of the trolls away in Ulik's skull, ending their threat, the end.
Thoughts: Well, for a comic where the ending was never in any doubt, this issue wasn't half bad. The fight scenes were bright and vibrant, and it was nice to see Thor come back and reclaim his rightful place in Asgardia. Sure, we knew how this one was ending going in, but this comic was a fine way to spend a few minutes after work.
Score: 6 1/2 out of 10.
Alas, poor Ulik!