Newly married, Jill strives to connect with her husband’s teen daughter Casey while raising her own young daughter, Lydia. Casey is secretive and difficult, but all the experts urge Jill to just give Casey time to adjust. However, when Jill’s aging mother mysteriously dies, Jill begins to suspect Casey. As Jill investigates her mother’s death together, Lydia's life may already be hanging in the balance.