despite interest in a sequel, touchstone pictures opted not to finance one. shyamalan set out to write "split" using a character he had written for "unbreakable" but pulled from its script due to balance issues. shyamalan realized the opportunity he had to create a trilogy of works, and used the ending of "split" to establish the film as within the "unbreakable" narrative. this included securing the rights to use willis's "unbreakable" character from walt disney studios, with the promise of including disney within the production and distribution of this third film alongside universal pictures. "split" was a financial and critical success, and by april 2017, shyamalan announced that he started the production process for "glass".