One morning Thor awoke to discover that Mjolnir had been stolen in the night by the giants, and he was enraged. With the help of Freya, Loki shapeshifted into a bird and flew to Jotunheim, the home of the giants. There, their king, Thrym told Loki that he had stolen the hammer, and buried it 8 miles under the earth, and the only way for Thor to get his beloved hammer back was for Freya to marry Thrym.