So I'm watching the "Maria and Draco" opera, and Locke is supposed to go check on Ceres. I go one direction, and the stagehand won't let me pass. I go the other direction, and it looks like there's a door, but it won't open or react when I investigate it, so it's not locked or anything. Am I missing something entirely here? Thanks :\

The exits are at the bottom of the screen. Just head down the aisles between the sections of chairs and you'll exit the seating area.