Résumé: Many Years Ago: Thor is trying to lift Mjolnir in the Great Weapons Hall of Asgard but doesn't succeed.
893 AD: Thor sails over the Baltic Sea. The sailors see a figure in the fog and it turns out to be the God Butcher, following them. They land on the shores of Neva River and Thor asks the people there for their gods. They don't react very friendly but then one god's horse comes down without him, spattered in blood. Thor follows the blood trail, encounters another dead god. Then the God Butcher confronts him and they fight. Thor remembers that, as a child, a god named Dagr went on a killing spree until he was executed by Odin. Thor is haunted by the face of Dagr for a long time afterwards. The fight continues until Thor hits the God Butcher with lightning.
The Present Day: Thor has defeated the God Butcher's servants and swears to find him by following the trail of dead gods.