Bryan Singer’s latest installment in the X-Men saga has a brand new trailer that is making waves on the internet.

‘Days of Future Past’ features both Ian McKellen and Patrick Stewart in their classic roles as Magneto and Professor Xavier, respectively, interacting with their past selves, played by Michael Fassbender and James McAvoy, in order to stop a terrifying new war before it has a chance to begin.

Chronologically this film takes place after last year’s film ‘The Wolverine’, which in turn takes place directly after ‘X-Men: The Last Stand’, which debuted in 2006.

A new ‘Wolverine’ film is also slated to come to theaters in 2017.

‘X-Men: Days of Future Past’ opens in theaters in the U.S. on May 23.