The Descendants star will step behind the camera for A Happening of Monumental Proportions, which is set in a Los Angeles school.

Written by Gary Lundy, the script for the project was a semi-finalist for the Nicholl Fellowship, and a finalist for the Writer's Lab at the Sundance Film Festival.

Greer will take on the film after she wraps War for the Planet of the Apes, in which she reprises her role as Cornelia, the wife of ape army leader Caesar.