Thor: Reign of Blood is a part-tongue-in-cheek-fairy-tale, part-grim-and-gritty-fantasy that tells two directly related chapters of Matt Fraction's series of Thor one-shots.
First is the story of the Ice Giant's Daughter, who after her father's death at the hands of Thor, has besieged Midgard with an unending winter. To end the onslaught of unprecedented cold and snow, the Ice Giant's Daughter demands that the gods of Asgard instruct the dwarves to forge for her their finest trinket. But will Loki's deceit be the end of the Ice Giant's Daughter? Will it be the end of Loki himself?
The second story focuses on Enchantress, who becomes infatuated with a necklace made by the dwarves, and pays them a carnal transaction to obtain it. Outraged, and perhaps a bit jealous, Odin takes the necklace from her. Even more indignant than Odin, Enchantress curses Midgard with a plague of the risen dead which only Thor can stop, piloting a Blood Colossus forged by Midgardian mortals.