The Amazing Spider-Man 2 opened in the U.K. this week and fans who got to see it before their friends in the U.S. also saw a brief clip at the end that teased X-Men: Days of Future Past. But Spider-Man was made by Sony and Days of Future Past by 20th Century Fox, so there needed to be some dealmaking in order for it to happen.
U.K. magazine Empire reports that the brief clip features Jennifer Lawrence as Mystique, plus Evan Jonigkeit and Lucas Hill. While this may seem to hint at some kind of crossover between the Spider-Man and X-Men universes, that’s not what’s happening here.
As Variety explains, it is actually due to talks between Sony and Fox that ultimately let Marc Webb direct the first two Amazing Spider-Man films (and eventually the third).
Webb had signed a two-picture deal with Fox Searchlight before making (500) Days of Summer back in 2009, so he was supposed to make another film for the studio. He had planned to make that movie after first Amazing Spider-Man, but it didn't happen. During talks between Sony and Fox to let Webb hold off on making the Fox film, Sony agreed to plug Days of Future Past at the end of Amazing Spider-Man 2 for free.
While both X-Men and Spider-Man are Marvel properties, the film rights reside at the different studios. (Fox also has the Fantastic Four.) The remaining characters are under the Marvel Studios umbrella at Disney, which is why they can easily crossover between films.
The Amazing Spider-Man 2 finally opens in the U.S. on May 2. Days of Future Past opens on May 23.