Thor: Ragnarok Comic-Con Trailer (2017): Check out the new trailer starring Tom Hiddleston, Chris Hemsworth, Cate Blanchett, and Idris Elba! br br After the events of Avengers: Age of Ultron, Thor, held captive on the planet Sakaar without his hammer, must win a gladiatorial duel against an old friend — the Hulk — in order to return to Asgard in time to stop the ruthless Hela and the impending Ragnarok, the doom of the Asgardian civilization.