During an advanced screening of Thor: Ragnarok at a Los Angeles movieplex, talk show host James Corden interrupted the film to present a special "4D version" of it. The audience appeared annoyed by the interruption until they realized the film's actual cast was on hand to act out a condensed low-budget depiction of the movie in real life.
Chris Hemsworth, the actor who plays Thor, came out first, in a bad blonde wig. He was soon followed by Cate Blanchett, Tom Hiddleston, Tessa Thompson, Mark Ruffalo and Jeff Goldblum. I really don't want to tell you more than that, you should just watch it.
If you haven't seen the film, there are possible spoilers. And if you have, I think you'll appreciate this stunt even more.