Jennifer Lawrence will reprise her role as Mystique in "X-Men: Apocalypse
Jennifer Lawrence will reprise her role as Mystique in "X-Men: Apocalypse." Pictured: Lawrence arrives at the premiere of "The Hunger Games: Mockingjay - Part 1," in Los Angeles in 2014. Reuters

“X-Men: Apocalypse” director Bryan Singer recently teased a video from the film’s Montreal set on his Instagram page. In the video, he can be seen saying that he is working late at night in an underground mansion hallway to shoot a secret scene. He did not reveal any details about the scene but he hopes that fans will enjoy it. He captioned the video, “bryanjaysingerLate night. #Xmen #XmenApocalypse.”

According to Web speculation, the “secret scene” is being shot in the hallway outside of Cerebro’s room underneath the Xavier School. It is apparently the same hallway that has appeared in the previous "X-Men" films.

In the comics, the Xavier School is a special institute founded by Professor Charles Xavier. It trains mutants to channel their powers so that a friendly human-mutant relationship can be created. The first student is Jean Grey.

Later, the professor recruits Bobby Drake, Warren Worthington III and Hank McCoy, who together form the original X-Men.

“X-Men: Apocalypse” will see super-powered mutants battling the dangerous enemy Apocalypse, who has the ability to change his physical form. In the comics, Apocalypse is an immortal mutant and was born 5,000 years ago in Aqaba. He is also known as the First One. He can access the powers of other mutants and recruits a group called the “Four Horseman” who aid him in his war against the X-Men.

Oscar Isaac will play Apocalypse. According to the actor, “He (Apocalypse) can be anything, he can do anything -- so those aspects … I think of the idea of the first mutant and the idea that he wouldn’t be called a mutant back then. What would he be? God. He would be a god on Earth. And he wouldn’t think of himself as a mutant,” Cinema Blend reported.

“X-Men: Apocalypse” opens May 27, 2016. Other cast members include James McAvoy, Michael Fassbender, Jennifer Lawrence, Nicholas Hoult, Rose Byrne, Tye Sheridan, Sophie Turner, Alexandra Shipp, Kodi Smit-McPhee, Evan Peters, Lucas Till, Ben Hardy, Lana Condor and Olivia Munn.