One major question mark surrounding the movie is the role of everyone's favourite mischief-loving baddie, Loki (Tom Hiddleston). Originally, it was announced that Loki wouldn't be appearing in the movie at all, with even Hiddleston himself confirming this, but more recently, Idris Elba (who plays Heimdall) confirmed that both himself and Loki will appear in the film. The scene reportedly features the pair of them as well as Thor, but beyond that, absolutely nothing is known. The Likely Answer: It's going to be a functional cameo and probably nothing else, just so Marvel can give fans a slight update on what's happening with Loki, considering how beloved the character is. As great as it would be to see him show up and help take down Ultron, there's no way it's going to happen. Expect no more than two or three minutes of banter from him.