The official trailer for the sequel to the 2011 'X-Men First Class' has been released online. 'X-Men: Days Of Future Past' sees the return of the film franchise's biggest characters and includes a few new faces as the ensemble cast combine to depict a time travelling story to save the mutants from their imminent destruction.

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Logan (Jackman) travels back in time to meet a young Prof X (James McAvoy)

The sequel trailer already rises important questions that need to be addressed in the upcoming sequel. The 2 minute long clip heavily features the return of 'Professor Charles Xavier' (Patrick Stewart), a character presumed to be dead after being killed by Jean Grey in 2006's 'X-Men: The Last Stand'. A resurrection perhaps?

The trailer does inform the audience that 'Xavier' joins forces with his old nemesis 'Magneto' (Ian McKellen) to devise a plan and save the mutant race. 'Magneto' and 'Xavier' seek the help of 'Wolverine/Logan' (Hugh Jackman) and ask him to travel back in time, meet their younger selves, to get their help and save their species in the future.

Watch the 'X-Men: Days Of Future Past' trailer here

Wolverine will visit the past that was featured in 2011's 'X-Men: First Class' with James McAvoy playing the younger Professor X and Michael Fassbender portraying a young 'Magneto'. The plot sees the present day mutants seek the help of mutant sin the past, to save the mutants of the future.

To call the premise complicated is an understatement!

"You're going to have to do for me what I once did for you," the resurrected 'Charles Xavier' tells 'Logan' before he travels through time.

"So, I wake up in my younger body and then what?" a dumbfounded Logan asks.

Prof X replies, "Find me and convince me of all this." "And where do I find you?"

"A different path. A darker path," a cautious and unnerving 'Charles Xavier' says.

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'X-Men:Days Of Future Past' poster feautring the young and old 'Magneto'

'X-Men: First Class' finished after the Cuban Missile Crisis and the trailer hints that 'Logan' will be travelling just after this event, to the mid-60s to find the younger mutants. In between the two different time periods, the clip also intertwines in key characters from the 13 year movie franchise, including Halle Berry as 'Storm', Anna Paquin as 'Rogue', Shawn Ashmore as 'iceman' and many more.

'X-Men: Days of Future Past' is set for release May 24th 2014.

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'X-Men' poster featuring the young and old 'Professor Xavier'