Here's The Official Plot Synopsis For M. Night Shyamalan's GLASS
Caution: spoilers for Split to follow.

Unless you've been living under a rock, you know that M. Night Shyamalan's Split (which arrived back in January, made critics happy, and went on to earn over $275M at the worldwide box office) was actually something of a surprise sequel to Shyamalan's Unbreakable. You also probably know that Shymalan's next project, Glass, will bring this unexpected trilogy to a close, and bring together all the major players from both Unbreakable and Split.
Today, we've got the first plot synopsis from the film, and with it comes the first suggestion of how all these characters may wind up interacting with one another. Let's take a look:
"From Unbreakable, Bruce Willis returns as David Dunn as does Samuel L. Jackson as Elijah Price, known also by his pseudonym Mr. Glass. Joining from Split are James McAvoy, reprising his role as Kevin Wendell Crumb and the multiple identities who reside within, and Anya Taylor-Joy as Casey Cooke, the only captive to survive an encounter with The Beast.
Following the conclusion of Split, Glass finds Dunn pursuing Crumb's superhuman figure of The Beast in a series of escalating encounters, while the shadowy presence of Price emerges as an orchestrator who holds secrets critical to both men.
This riveting culmination of his worldwide blockbusters will be produced by Shyamalan and Jason Blum, who also produced the writer/director's previous two films for Universal. They produce again with Ashwin Rajan and Marc Bienstock, and Steven Schneider, who will executive produce."