When Laura Franklin's younger sister Shirley comes into the world, Laura instantly resents her, and soon begins wish and even to pray that her baby sister will die. But after saving Shirley's life in a fire, she experiences a complete change of feeling, and becomes very affectionate and protective towards her. Later, as the sisters grow up and fall in love, Laura begins to realise that the burden of her love for Shirley has had a dramatic effect on both their lives.