Glass is the third installment of M. Night Shyamalan’s Unbreakable or Eastrail 177 series. Unbreakable introduced us to David Dunn who learns he has superhuman powers with the help of Elijah Price. Elijah has the nickname of Mr. Glass due to the brittleness of his bones and how easily his body is damaged. He comes to discover David from pursuing his theory that if there are people who are as frail as him, there should be those on the other end of the spectrum who are superstrong and impervious to injury.
Split was revealed to be set in the same series as Unbreakable when you see the cameo of David Dunn near the end of the movie. Split follows the character of Kevin Crumb. Kevin has multiple personalities with one of them being the Beast. The Beast is a transformation of Kevin’s psyche into a merciless and cannibalistic sociopath with superhuman abilities. Due to his childhood abuse, the Beast wants to rid the world of those who have been untouched by suffering.
Glass sees all three (Elijah, David, and Kevin) incarcerated in the same mental facility. They are being treated for delusions of grandeur. Eventually Elijah convinces Kevin to bring the Beast forward and help him escape. David then plans his escape so he can hunt down the two villains and return them to justice.
The Unbreakable series for me is the truest form of superhero movie. There is very little CGI and the characters are much more believable as heroes and villains than in the Marvel & DC films. Glass will complete the ultimate superhero trilogy.