Avengers Assemble Season 2 Episode 1

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.