A lost girl, an automaton and a sprawling map of a beguiling, unsettling city.Wren Lithgow has been following her concert pianist mother around the cities of Europe for almost two decades. When they arrive in the mysterious city-state of O, where she was conceived during the civil war, Wren resolves to track down the 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.