His initial plan was for “David and the Horde bump into each other at the train station, and David follows him.”
As the director told Vulture in an excellent new interview (seriously, go read the whole thing, it’s excellent), the Horde showed up in his original script for Unbreakable .
In Glass, those two men — plus Samuel L. Jackson’s brittle-boned fiend Mr. Glass from Unbreakable — will meet.
Which begs the question: What twist does Shyamalan have waiting at the end of Glass?