Mighty Thor by Matt Fraction Vol. 1

Collects The Mighty Thor #1-6. The Silver Surfer - herald of Galactus, devourer of worlds - recognizes the Worldheart as the one object that could forever sate his master's apocalyptic appetite. Now, the Surfer has come to Asgard to claim a prize Odin will not surrender without a fight - and Thor is caught in the middle. Will he entrust the Worldheart to the Surfer?