When filmmaker Ian Cheney moves to New York City and discovers skies almost completely devoid of stars, a simple question – what do we lose, when we lose the night? – spawns a journey to America's brightest and darkest corners. Astronomers, cancer researchers, ecologists and philosophers provide glimpses of what is lost in the glare of city lights. Blending a humorous, searching tone with poetic footage of the night sky, what unravels is an introduction to the science of the dark, and an exploration of the human relationship to the stars.