Most summer classes do not require students to don hard hats and protective padding for course credit, nor do they hold “classes” 200 feet underground. But the students of Jason Knowles’ Multimedia and Film Production summer intensive class at Georgia Southern University have found themselves in that situation twice since the beginning of June. As part of Knowles’ ambitious summer project — completing a feature-length action-adventure film before the beginning of August — the students and a small cast spent several days filming the feature’s climax deep in the caverns of Raccoon Mountain in Chattanooga, Tennessee.