Lily Watkins (Jean Simmons), a maid of humble birth, falls in love with her master Stephen Lowry (Stewart Granger). In order to get her master's attention and attention, she threatens her master to be her housekeeper, otherwise she will tell the police that he poisoned and killed his wife. After becoming a housekeeper, Lily drives out all the servants in the house, hoping that she can only stay with her master. Stephen, who is pressed by Lily step by step, can't stand it. On a foggy night, he picked up his walking stick and ran into the fog, determined to get rid of Lily.