Topside tells the story of a mother and her 5-year-old daughter who live in a New York City subway tunnel community. When Nikki and her daughter Little are suddenly evicted from the underground, they must face a grim future up top. Little has never known anything but the tunnels, so she is terrified by the noise, bustle, and people as Nikki tries to find a way back to the comparative security of their subterranean home.