The new footage started with Sarah Paulson’s character looking right into the camera. “It’s amazing to meet you,” she said. “It’s simply extraordinary.” As she speaks, there are shots of some kind of imposing institution she’s likely inside of. She explains to someone that she’s a psychologist who specializes in a growing field she refers to as “delusions of grandeur.” Or, basically, people who believe they’re superheroes.
The film cuts to reveal who she’s talking to. It’s Mr. Glass (Samuel L. Jackson), the Horde (James McAvoy), and David Dunn (Bruce Willis), all characters from Shyamalan’s previous films. They are all in the same room, in what we think is a mental institution, sitting next to each other. Each of the characters has aged significantly, with Mr. Glass’s hair even wilder than before, and David Dunn with a grey beard. She proceeds to explain how each of them believes they have special powers and runs down what each character believes about themselves.
She begins to explain who Mr. Glass, the Horde, and David Dunn are and we see brief glimpses of a comic book shop, Dunn in the rain, a train, just lots of iconography from the three characters. The focus begins with Dunn, who we see in his house explaining to someone he’s “in security” and, when he touches people, he can see their secrets. The doctor sums him up by saying “you think you are a protector.”
Next is Kevin Wendell Crumb, McAvoy’s character, with 24 different personalities sometimes referred to as the Horde. The doctor explains that she believes that he has multiple personalities inside him, but she doesn’t believe that one of those is a superhuman called the Beast. As she explains this, we see that Kevin’s penchant for kidnapping has continued, as he’s tied up four cheerleaders. “Why do you believe you are more than human?” the doctor asks.
But then the doctor is interrupted. “And yet, it is true,” Mr. Glass says. “My bones break very easily,” he says as he breaks down, no pun intended, all of the breaks he’s had in his life. “This is not a cartoon,” he continues. “This is the real world. But some of us don’t die with bullets.” Cut to a scene of Kevin, as the Beast, being shot at and living. “Some of us can bend steel.” Cut to a shot of David bending steel. “I’ve been waiting for the world to see that we exist.”
There’s a shot of Casey (Anya Taylor-Joy reprising her role from Split) walking in a hallway. Another of her reuniting with Kevin and he, as the child Hedwig, saying “No fricking way.” A shot of Mr. Glass asking Kevin, “May I meet the Beast?” Kevin emerges from the dark as The Beast and gets right up in Mr. Glass’ face. “I believe that counts as the bad guys teaming up,” he says.
Now it jumps into full-on montage mode. Lots of action. The Beast hurtling across a lawn on all fours. David fighting, trying to save some people, he gets thrown around and more. “A lot of people are going to die,” Mr. Glass says at some point. Then, someone asks him his name. “First name, Mister, last name...” and the title comes up. “Glass.”