Lea walks her usual route through the city when a young man steals her bag. She chases him into an alley but quickly loses her bearings—each alley leads into yet another alley, the sounds of the city fade away, and the thief is nowhere to be seen. Hopelessly searching for an exit, she eventually encounters Dee, one of the alleyfolk who obsessively makes maps of his surroundings and is convinced that the alleys have been gradually narrowing over time. The more of these alleyfolk Lea gets to know, the more she sees that they agree: the labyrinth they inhabit is shifting, creating a state of deep uncertainty. When the presence of the thief becomes a subject of contention, Lea finds herself entangled in the affairs of a world fated to end soon. Closing Act examines the complex networks that make up a city and finds a strange, shifting environment within it, one where its inhabitants face a looming existential threat.