The Great Light: Lorenz Ferleitner has worked his way up from a poor but gifted farm boy to a recognized master builder. When a new cathedral is to be built, he is given the honor of carrying out the task. He would like to commission the unknown young painter Fritz Rasmussen to decorate the dome. The director of the art academy, Professor Marquardt, however, wants to employ his untalented nephew for the painting work. A bitter conflict unfolds.