Los Angeles - X-Men: Days of Future Past is "not just a sequel".
Director Bryan Singer - who will helm the ambitious blockbuster project, uniting the casts of the original X-Men trilogy and 2011 prequel X-Men: First Class - insists the new film won't just be a follow-up to the 2011 film or 2006's X-Men: The Last Stand, but a completely original movie.
He explained: "We also wanted to play with the notion of different times and stuff like the way that time affects destinies. It enables the film to not just be a sequel to First Class or X-Men 3 but to actually be its own thing."
With a time-travelling plot, Singer was wary about the film being too confusing - but was assured it made sense by another famous director.
Old and young characters together
He said: "I think we've got it figured out. I pitched it to James Cameron when I was in New Zealand last year and he said, 'Yes, that makes sense.'"
Meanwhile, Singer hopes the mix of older and newer faces - including Sir Ian McKellen as Magneto from the original trilogy and Jennifer Lawrence as Mystique from First Class - will entice all audiences.
He added to SFX: "We wanted an opportunity to bring some of the favourite older and younger characters together."
Other A-list stars who are set to reprise their roles from the various X-Men films include Hugh Jackman, Sir Patrick Stewart, Halle Berry, Anna Paquin, Shawn Ashmore, Ellen Page, Michael Fassbender and James McAvoy.