During the events of the "Secret Invasion
" storyline, Thor rescues and heals ally Beta Ray Bill
, who after being temporarily given Mjolnir, aids Thor in a battle against an invading force of alien Skrulls
Thor also participates in the final battle against the Skrull forces, and is forced to sacrifice Avenger ally the Wasp
Due to a deception by Loki, Thor battles and kills his grandfather Bor
, and is banished from Asgard. With Thor's hammer Mjolnir damaged in that battle, Thor seeks out Doctor Strange
, who is only able to repair the hammer by transferring the Odinforce from Thor to Mjolnir, binding the two in a symbiotic
relationship. With the repaired hammer, Thor is able to draw out the imprisoned Sif, but her host then dies.