One of the big mysteries of Comic-Con 2013 is what 20th Century Fox will be presenting on their Saturday, July 20 panel in Hall H, aside from The Wolverine and Dawn of the Planet of the Apes. Insiders claim that one of the big surprises is that more than a dozen X-Men: Days of Future Past cast members will make an appearance, and that they will reveal several of the secret character identities. There will be spoilers throughout the rest of the story, so read on at your own risk.

Peter Dinklage will be confirmed as Bolivar Trask in this sequel, although recent set photos from May all but revealed his identity already. While many speculated that Josh Helman is playing Cyclops, insiders reveal that he is actually playing a young William Stryker, who was portrayed by Brian Cox in X2: X-Men United.

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In addition, plot details have surfaced that reveal how time travel comes into play in this superhero sequel. Ellen Page returns as Kitty Pryde X-Men: The Last Stand, who uses time travel to send Hugh Jackman's Wolverine into the past. There he meets the younger versions of Professor X, Mystique, and Magneto, played by James McAvoy, Jennifer Lawrence, and Michael Fassbender. However, he is still under Kitty's "time-travel trance," causing the X-Men to find a mutant who can take Kitty's time-travel abilities to bring Logan back to the future, which is likely where Anna Paquin's Rogue comes into play.

Stay tuned to find out more about X-Men: Days of Future Past as we near closer to the Saturday panel.