Los Angeles, March 1928: On a beautiful Saturday morning in a working-class suburb, single mother Christine Collins says goodbye to her nine-year-old son, Walter, and leaves for her job as a telephone operator. But when Christine returns to their modest home, she is confronted with every parent's worst nightmare: her son has vanished. An exhaustive and fruitless search ensues, but Walter has disappeared without a trace--until five months later, when a child--claiming to be her boy--is returned by police who are eager to bask in the public-relations coup of reuniting mother and child. Dazed by the swirl of cops, reporters, photographers and her own conflicted emotions, Christine is persuaded to take the boy home. But in her heart, she knows he is not Walter. As she pushes authorities to keep looking for her real son, Christine learns that in Prohibition-era L.A., women don't challenge the system and live to tell their story. Slandered as delusional and unfit, she finds an ally in community activist Reverend Gustav Briegleb, who helps her fight the city to look for her missing boy. Facing corrupt police who question her sanity and a skeptical public hungry for a fairy-tale ending, Christine desperately hunts for answers. As she searches, she becomes an unlikely heroine for the poor and downtrodden who have been systematically abused and swept aside by the police state that has gripped L.A. Now, one woman's quest won't stop until she finds her son--unless those assigned to protect and serve silence her for good.