(EW.com) -- It's a casting "X"-gravaganza! Director Bryan Singer tweeted Tuesday that Ian McKellen and Patrick Stewart will be reprising their respective roles as Magneto and Prof. X in "X-Men: Days of Future Past," and they'll be joined by "X-Men: First Class" stars Michael Fassbender as Magneto and James McAvoy as Prof. X. Wait, what? For the geek uninitiated, "Days of Future Past" is also the title of an X-Men comic book storyline from 1981, which alternated between a dystopian future in which mutants are living in internment camps, and the present day mutants working to prevent that future from happening.
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Ian McKellen and Patrick Stewart have been cast in "X-Men: Days of Future Past"
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McKellen will reprise his role as Magneto and Stewart will be back as Prof. X
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Michael Fassbender and James McAvoy of "X-Men: First Class" will also portray Magneto and Prof. X
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The casting news hints that the next film will reconstitute a 1981 comic book storyline
All @placeholder would say in his final tweet: "More to come..."