For the last 17 years, Harry and Zara King’s lives have revolved around their only daughter, Sophie. One day, Sophie leaves the house and doesn’t come home. Six weeks later, the police are no closer to finding her than when they started. Harry and Zara have questioned everyone who has ever had any connection to Sophie, to no avail. Except there’s one house on their block --- number 210, across the street --- whose occupant refuses to break his silence. As the question mark over number 210 devolves into obsession, Harry and Zara are forced to examine their own lives. They realize they have grown apart, suffering in separate spheres of grief. And as they try to find their way back to each other, they must face the truth about their daughter: who she was, how she changed and why she disappeared.