Thirty-nine-year-old British photographer and single mom Tess has a good life that revolves around her nine-year-old son Joe and her thriving career. Before long she meets and marries Greg, a charismatic American pediatric heart surgeon, who is soon offered a dream job in Boston along with a part-time teaching position at Harvard. Tess and Joe have a hard time adapting to life in an American city. More worryingly, Tess notices that their new neighbors, and even some strangers, seem to recognize her husband, which he waves off as coincidence. As these strange encounters continue to occur, however, she begins to suspect that something is not quite right. In secret, she starts to look into Greg's past and discovers more questions than answers about the man she has followed across the ocean--the man who is the father of their new baby daughter.