Seventeen years after she was abducted by a stranger named Benjamin McKay (Jason Isaacs), twenty-three-year-old Leanne Dargon (Saoirse Ronan), who has been in his captivity all this time, is discovered, and eventually reunited with her biological parents, Marcy (Cynthia Nixon) and Glen Dargon (David Warshofsky), while Ben is now in prison charged with her kidnapping. Ben was able to hide her locked in his basement all of this time, telling her that he saved her from world destruction, which she would have no reason not to believe. Leanne has no true recollection of her time before Ben, who renamed her "Leia", and thus is the only family she has ever known. Over those seventeen years, Marcy and Glen dealt with the abduction in different ways, Marcy, whose primary focus was and still is Leanne, to the point of never having returned to work. Marcy, Glen, and Leia enter into their reunion with this history. So while Marcy and Glen have a memory of their six-year-old daughter who they want back in a young adult form, Leia only sees in front of her two strangers. Their parent/offspring relationship is thus formal and strained at best. But it takes a turn when Marcy discovers just how much of an attachment Leia still has to Ben, who Marcy only sees as the man who destroyed their family. Marcy goes to extreme measures to get back the "Leanne" she so desperately wants, at the possible expense of everything else in her life.