In 1913, young Irish emigrant Eva Downey is trapped in London with a remote father and hostile stepmother. When she is awarded a legacy from an old suffragette to attend a finishing school in Kent, she jumps at the chance. At the school, she finds kinship and later falls in love with her teacher Christopher Shandlin, her intellectual equal.
But when war does break out, her fanatical and disapproving stepsister Grace forces a choice on Eva. She must present Shandlin, who refuses to fight, with a white feather of cowardice, or no money will be given for her sister Imelds life-saving treatment in Switzerland. Caught in a dilemma, she chooses her sister over her lover, a decision which will have irrevocable consequences for both her and Christopher and haunt her for the rest of her life.