"Changeling" (2008)

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.