Thor's hammer is stolen by a frost. In order to get it back he dresses as a maiden and gets it back and uses it on the frost giant.
Balder the god of light, joy, beauty, and wisdom, but his mother made him almost invincible. His mother though didn't have mistletoe make a promise to not harm him, so Loki managed to kill him with it.
When Loki see how beautiful Freya's necklace is he tires to steal it. Heimdall stops him though and gets the necklace back to Freya.