When Red Skull comes crashing to Earth with a fleet of alien ships chasing him, the Avengers learn there's a villain in their midst a thousand times more dangerous than the Cabal ever was by the name of Thanos. Upon finding the Power Infinity Gem in Red Skull's possession, the Avengers are led to a gamma-high city to look for something called Arsenal.

Hulk and Thor are tricked into a battle and transported to Valhalla to find out who is the strongest, once and for all. But under Hela's rule, only the loser of their contest may return to Earth while the winner will become her consort and champion.