Prequels and sequels are becoming a regular thing in Hollywood these days but it’s very rare to see a film that has both its young AND old versions of characters having to work together.

That is exactly the case for Marvel’s latest big-screen achievement as the X-Men team reunite again for the much-anticipated Days of Future Past. The official trailer for the superhero blockbuster has finally been unveiled online.

Directed by the returning Bryan Singer (X-Men, X2), the film sees Professor Charles Xavier (Patrick Stewart) and arch nemesis Magneto (Ian McKellen) having to join forces in order to save the world from being destroyed. To do that, they and other X-Men including Wolverine (Hugh Jackman) travel back in time to try and alter the decisions of their younger selves in order to prevent a terrible future.

Cast members from both the original trilogy and the recent prequel First Class (2011) feature in the epic Marvel outing. Halle Berry (Storm), Anna Paquin (Rogue) and Ellen Page (Kitty Pryde) reprise their roles from the 2000-2006 series while James McAvoy (Young Xavier), Michael Fassbender (Young Magneto), Jennifer Lawrence (Mystique) and Nicholas Hoult (Beast) return from the latter film.

Peter Dinklage (The Station Agent, Game of Thrones) and Omar Sy (Intouchable) both make their debuts in the superhero franchise.

X-Men: Days of Future Past will hit cinemas on May 22nd 2014.