In 1928 Los Angeles, single mother Christine Collins returns home to find her 9-year-old son, Walter, missing. Five months later, the police reunite mother and son in a reunion that Christine immediately suspects is a ruse. As she delves deeper into the truth, Christine's quest exposes a world of corruption, mental asylum abuse, and cover-ups by corrupt clergyman Reverend Gustav Briegleb and apathetic city authorities.