Samantha's life is turned upside down after a terrifying car accident leaves her 10-year-old daughter Cassie severely injured. Already struggling to balance her consuming work life with her deteriorating marriage to Cassie's father, Tom, Samantha hires a live-in-nurse Margaret to help her daughter recover. Margaret, embittered over the loss of her own child, embarks on a mission of vengeance against Samantha and Tom to get back the daughter she thinks is hers.