Based on a novel by Marcia Davenport, the son of a steel mill owner falls in love with a house maid; but her father was injured in the mill and hates the owners.
In Pittsburgh, Mary Rafferty (Greer Garson) tells her father Pat Rafferty (Lionel Barrymore) that she may work in the home of William Scott (Donald Crisp). Jim Brennan (Preston Foster) says he will board in her empty room. Mary sees Paul Scott (Gregory Peck) welcomed home. She starts as a servant and meets the family. Paul believes steel is in their family and recommends the open hearth he saw in Germany. He works on it and goes to Jim's room on Sunday. Pat gets angry with Mary and says Scott makes men work twelve hours a day, and he lost use of his legs. Paul leaves, and Mary walks with him. She sings for Paul. Mary serves and won't let Constance Scott (Marsha Hunt) sneak out. Mrs. Scott (Gladys Cooper) thanks Mary and invites her to Boston for the wedding of Willie Scott (Dan Duryea). On the boat Mary chaperones Constance, and Paul kisses Mary goodnight. Paul works to perfect the open hearth but fails again. Mary serves him a late supper. Paul says he needs to talk with her and asks her to marry him. Mary tells Mrs. Scott she must see her father. Constance and Giles (John Warburton) tell William Scott they are married. They offer Mary a job in England. Mrs. Scott gives Mary a coat. Jim shows Mary the good steel they made, but Pat suspects she is in trouble. Jim asks her to stay and marry him, but she says Paul wants to marry her.
Two years later Constance gets a letter from Paul and asks Mary why she has not answered his letters. She reads a letter from Paul and cries. Paul takes Louise (Jessica Tandy) home. William Scott has been ill and asks about Louise, but Paul says he is in love with Mary. William telegraphs Mary to return and asks her to marry Paul. She is glad to see Mrs. Scott, and Paul finds her and kisses her. Willie tells his father and Paul that his detectives said Jim's men are planning violence. Someone attacks the house and injures Paul. William tells Willie to get the strikebreakers. Mary tells Jim and asks him to go to Scott's office, but he says never. Mary tells her father that she is going to marry Paul. Pat curses it, but Jim blesses her. Mary tells William she said he would meet them half way. William sends Ted Scott (Marshall Thompson) to pay off the thugs, but he gets drunk. William and Paul meet Jim and the union leaders. William grants a five-cent increase, a safety rail, and a union shop. Pat says he is lying, but no one agrees with that. Willie arrives with the strikebreakers, and shots are fired, killing Pat and William. Paul comes to Mary's flat to take her home, but she won't go with him.
Paul marries Louise and has a son. Louise complains her son plays with workers. Mrs. Scott visits Mary and tells her she is leaving her a fifth share; then she falls ill. Mary helps take care of her, and she dies. Willie says he has Ted's proxy and offers Constance $2 million. Louise wants the mill sold too. Mary says she has a share and wants to keep the mill, but Constance is in debt. Mary offers Constance her profits, and Constance says she won't sell. Paul tells Louise to leave and drives Mary home.
Fine character portraits distinguish this drama of moral
choices as they reveal whether they are selfish or care about