By the time James McAvoy signed on to play the villainous Kevin Wendell Crumb in 2017’s Split, it didn’t even occur to the actor that his movie might occupy the same universe as 2000’s Unbreakable. Writer-director M. Night Shyamalan wised him up during rehearsals.

“We were chatting and he said, ‘Well, maybe if this one does well, we’ll do another one,’ ” McAvoy told EW in a recent interview. “I was like, ‘Really? We’re going to do a sequel to Split?’ He was like, ‘Yeah, you know, bring back David and all that.’ And I was like, David?” The filmmaker meant Bruce Willis’ David Dunn, the workingman superhero of Unbreakable. That’s when McAvoy knew: “Oh, wait a minute…”

One of last year’s greatest magic tricks happened on cinema screens showing Split, which became a box office hit. McAvoy played a killer with multiple personalities, and Anya Taylor-Joy was his kidnapped victim in a horror thriller that seemed to have no connection with any previous film for almost its entire running time. But at the movie’s conclusion, Willis appeared as Dunn, uttering the name of Unbreakable’s fragile-boned supervillain portrayed by Samuel L. Jackson: Mr. Glass. The twist was a doozy even by the standards of the filmmaker who brought us The Sixth Sense.

Shyamalan’s new film, Glass (out Jan. 18), will fulfill the tacit promise of that ending by leading with Willis’ Dunn, Jackson’s Glass (a.k.a. Elijah Price), Taylor-Joy’s Casey Cooke, and the multiple personalities inhabiting McAvoy’s Crumb, both familiar and previously unseen. “We get to spend some time with some new people that live inside Kevin,” McAvoy said. Those are not the only franchise returnees: Charlayne Woodard, who played Elijah’s mom, and Spencer Treat Clark, who played David’s son, also make appearances. “[They] play a big role,” Shyamalan teased to EW.

At this year’s CinemaCon, a trailer for Glass featured footage of Dunn, Price, and Crumb in the same facility, receiving treatment from a psychiatrist. “She deals with people that think they’re comic-book characters,” Shyamalan said of the doctor, portrayed by Sarah Paulson. “It’s kind of the modern-day equivalent of ‘I think I’m Jesus’ or ‘I’m an emperor.’ ”

See exclusive images from Glass, and a behind-the-scenes shot of Willis and Shyamalan, below.

Image zoom Jessica Kourkounis/Universal

Image zoom Jessica Kourkounis/Universal

Image zoom Jessica Kourkounis/Universal

Image zoom Jessica Kourkounis/Universal