It's a warm day in august on the Montreal set of X-Men: Days of Future Past, but Hugh Jackman and Michael Fassbender are having a chilly moment. Wolverine (Jackman) has traveled from the near future where he hates Magneto back to 1973, where, it turns out, he also hates him. At the moment, the mutants are talking smack aboard a private plane bound for Paris. ''So you were always an a--hole,'' says Jackman. To which Fassbender as the younger Magneto responds, ''I take it we're not friends in the future?''
The collision of two eras is at the heart of the latest X-Men installment, due in theaters May 23, 2014. Days of Future Past was inspired by the 1981 Chris Claremont John Byrne comic-book story line of the same name. It's an ambitious, $200 million-plus saga that combines the cast of the original X-Men trilogy (Jackman, Patrick Stewart, Ian McKellen, Halle Berry, Anna Paquin) with that of 2011's hit prequel First Class (Fassbender, James McAvoy, Jennifer Lawrence, Nicholas Hoult). It also returns Bryan Singer to the director's chair after launching the series with 2000's X-Men and 2003's X2. ''I love the franchise,'' says Singer. ''I have very strong feelings about ways to explore it. So a chance to work with the new cast as a director and then to reunite with old friends like Hugh, Patrick, and Ian was a thrill for me.''
And why exactly are the decades colliding? It seems that the near-future Professor X (Stewart) and Magneto (McKellen) must send Wolverine back to the 1970s to alter a course of events involving Mystique (Lawrence) and mutant-hunting robots called Sentinels, created by industrialist Bolivar Trask (Game of Thrones star Peter Dinklage).
While First Class focused more on Magneto's origins, Days of Future Past turns the spotlight on McAvoy's troubled telepath, Charles Xavier. ''Wolverine basically plays the Charles Xavier role in this movie and I kind of play the Wolverine role,'' says McAvoy. ''I'm really f---ing grumpy and I'm also struggling to figure out who I am.'' And the character's evolution will have more than its share of tragedy before the final credits. Says Singer: ''It's a darker movie. It's a story of enormous loss and a sense of hopelessness and a desire to change events, change the future. And things go wrong.''
Adding to a stressful mission, Wolverine (Hugh Jackman) must reunite an estranged Erik Lehnsherr (Michael Fassbender) and Charles Xavier (James McAvoy). ''He's on a ticking clock,'' says Jackman. ''He is the last person on the planet who should be sent. Patience is not his strongest suit.''
Hank McCoy, a.k.a. Beast (Nicholas Hoult), tackles Erik (Fassbender) in an outdoor fountain out of loyalty to Erik's rival Charles. ''There's bad blood because of everything Erik's done to Charles,'' explains Hoult. ''Obviously Hank is on Charles' side completely.''
X's Hover Chair
The original Magneto (Ian McKellen) and Professor X (Patrick Stewart) descend from the X-Jet during a sequence set in the near future. ''Xavier's chair is a hover chair,'' says director Bryan Singer. ''That's something I wanted to do from the comic that I hadn't seen yet.''
New Mutant Foe
Peter Dinklage's Bolivar Trask, on a visit to the Oval Office, isn't your typical mutant-hating villain. ''He's actually kind of a peace lover,'' says Singer. ''He sees the advent of mutants as a way to unite people. There's this moment where he basically explains when modern men came along, it meant extinction for the Neanderthal; now humans are the Neanderthal, so this fight is for our survival as a species.''
Jennifer Lawrence's shape-shifter Mystique is more grown-up (and badass) in Days of Future Past. ''It's 10 years after X-Men: First Class,'' Singer explains. ''She's moving closer and closer to becoming the Mystique we know from X-Men and X2.''
Freed by Wolverine and Charles after being imprisoned, Fassbender's Erik reclaims his familiar Magneto helmet. ''In First Class, we learn how [Erik and Charles] became frenemies,'' explains Singer. ''In this, we learn how they became Magneto and Professor X.''