As successful as Marvel Studios has become, there’s still one thing we haven’t seen yet: a major movie crossover with other Marvel characters owned by different movie studios. Imagine Spider-Man and the X-Men fighting alongside the Avengers—it would be the biggest film ever. Unfortunately, as the rights to these characters all belong to different companies, we might not see such a crossover in the near future. However, in a new interview, Marvel comics creator and icon Stan Lee addresses the potential for a major multi-studio crossover, and it’s the most hopeful answer we’ve gotten yet.

Lee attended a book signing and Q&A event on Saturday with Roy Thomas (his successor as editor-in-chief at Marvel) and filmmaker/huge comic book nerd Kevin Smith at the Hammer museum to celebrate Marvel’s 75th anniversary. During the Q&A, a fan dressed as Captain America asked Lee if we’d ever see the Avengers, Spider-Man, and the X-Men all together in one huge crossover film. Here’s what Lee had to say:

It’s something that Marvel is very concerned about. It’s very difficult to bring ‘em all together because these characters are so successful and make so much money that the studios that have the rights don’t want to let them go. So that’s something that all the lawyers and all the production companies have to work out. Whether they get it worked out, I don’t know.

Typically, when crossover potential has been brought up in the past, Marvel president Kevin Feige doesn’t have much of an answer, so this response from Lee is a bit more optimistic—it also seems to imply that some talks have taken place between studios already, and it’s mostly a matter of money.

Lee went on to add, “It is a shame that [Disney] Marvel can’t distribute every one of them. Because then we could put them all together … in a movie that would make a hundred trillion dollars!” And he’s definitely right about that. A major, multi-studio crossover featuring all of these beloved Marvel superheroes would effortlessly become the highest-grossing film of all time.

You can watch the rest of the Q&A and talk below, in which Lee also confirms that he’ll make a cameo in the fourth episode of ‘Agent Carter,’ and describes his cameo in the upcoming ‘Avengers: Age of Ultron’ as his best yet.

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