The clip, released Thursday, features Jackson's Elijah Price, aka Mr. Glass, being joined by Willis' super-powered David Dunn and McAvoy's demented Beast inside a mental hospital.
A doctor, portrayed by Sarah Paulson, hopes to treat the three men by proving to them that they do not possess superpowers.
Mr. Glass then sets his plan into motion to prove that superpowers do exist when he recruits the Beast to break out of the hospital, leading up to an epic confrontation with Dunn.
"I need your abilities to get us all out of here. To show the world we exist," Mr. Glass says to the Beast. "That sounds like the bad guys teaming up."
Glass is set to arrive in theaters on Ja. 18, 2019. The film will work as both a sequel to Unbreakable and Split, both directed by Shyamalan.