Thor, Vol. 1

Thor and Ulik did battle to claim a crystal... a gem that both require to save their respective homes. Mimir requires the gem to discern the location of the vanished Odin, while the trolls need the gem's power to drive out an invader, Trogg, from another dimension. When Thor learns that the trolls need the gem to save their own home, he agrees to travel with Ulik in an attempt to overcome Trogg without using the gem.