A lost girl and a sprawling map of an unsettling city. Wren Lithgow has followed her concert pianist mother around the cities of Europe for almost two decades. When they arrive in the mysterious city-state of O, where Wren was conceived during a time of civil war, she resolves to find man she believes is her father. As the city closes in around her, Wren gives herself over to a place of which she understands nothing, but to which she feels a profound connection, in a story of the watchers and the watched, the ways in which we conceive of home and, finally, the possibility of living on our own terms.