In the official teaser trailer for Thor: Ragnarok, we see the titular character (Chris Hemsworth) wrapped in chains and falling toward us from a great height. He dangles in the air and we hear him say, "Now I know what you're thinking. 'How did this happen?' Well, it's a long story."
We're then introduced to the unforgiving, vicious villain of the film, Hela (Cate Blanchett). Loki (Tom Hiddleston) makes an appearance as well before Thor, sporting a sharp hair cut, is thrust into a gladiatorial contest with the Incredible Hulk. Upon seeing his competitor, he yells out, "We know each other!" Thor then addresses the audience: "He's a friend from work!"