The Changeling

A millionaire's little son, while out walking with his nurse, slipped away and mysteriously disappeared. Detectives scoured the country far and wide, but without result. Finally the conclusion was regretfully reached that the little chap must be dead, for the handsome rewards offered for his recovery would have tempted any one who knew of his whereabouts. An unscrupulous woman, who lived by her wits, read an account of the affair, and was amazed by the startling resemblance the missing boy bore to her own son. She decided to take advantage of the likeness, and presented herself at the wealthy widower's home with her son. The child was at once accepted as the missing heir. The millionaire offered her employment as nurse to his "son," and the woman and her child seemed assured of comfort and luxury as long as they lived. The millionaire's child had not died. When he ran away from his nurse he hid in a freight car, intending to frighten her, but the Joke became serious when the train ... - IMDb