It’s one of the biggest Marvel movies to date, when groups of heroes from three different universes — the Avengers, Wakandans, and the New Avengers from Earth 616, the Fantastic Four from Earth-828, and the “original” X-Men from a separate universe — converge to face a major threat: Doctor Doom (Robert Downey Jr.). That’s right, the X-Men finally join the Marvel Cinematic Universe in a huge way, and surely, things will never be the same in the MCU after this one.

Starring: Robert Downey Jr., Chris Evans, Chris Hemsworth, Pedro Pascal, Paul Rudd, Anthony Mackie, Florence Pugh, Vanessa Kirby, Ebon Moss-Bachrach, Wyatt Russell, Channing Tatum, Simu Liu, Ian McKellen, Hayley Atwell, Tom Hiddleston, James Marsden, Patrick Stewart, Joseph Quinn, Sebastian Stan, David Harbour, Letitia Wright, Lewis Pullman, Kelsey Grammer, Danny Ramirez, Kathryn Newton, Winston Duke, Alan Cumming, Hannah John-Kamen, Rebecca Romijn, and more

When it premieres: Dec. 18 in theaters