#a little rectangle of light

The inside of the Opera House–at least, the backstage inside–put Agnes strongly in mind of the clock her brother had taken apart to find the tick. It was hardly a building. It was more like a machine. Sets and curtains and ropes hung in the darkness like dreadful things in a forgotten cellar. The stage was only a small part of the place, a little rectangle of light in a huge, complicated darkness full of significant machinery…

Terry Pratchett, Maskerade