Thor - Siege Aftermath (2011)

Collects Thor (2007-2011) #611-614 & Thor #179-181.
A crafty loophole in Loki's contract with Hela allows Mephisto, the lord of Hell and the D'sir's new master, to unleash the carnivorous killers on Asgard again. Plus: In a classic tale from the titanic triumvirate of Stan Lee, Jack Kirby and Neal Adams, Thor finds himself trapped in Loki's body -- and in Hell!