What is the main conflict in the novel, The Heart of Midlothian?

The moral dilemma that faces Jeanie Deans, and with which she deals successfully, is at the core of the novel. Even when Effie begs her sister to lie for her, to save her life (child murder was a capital crime), Jeanie remains firmly attached to her highly moral upbringing. She adheres to what she sees as a higher morality than sisterly love; her principal love is for God, whom she will not betray, even for her own flesh and blood. This rigidity of conscience results from the childhood that Jeanie has spent in the home of her Covenanter father, David Deans. Therefore,the attitude that she reveals is not only believable, but inevitable. Her journey to London to free Effie is not only heroic, it is of-a-piece with Jeanie's firm principles: she has refused to "save" her sister, so she must do all that she can to prevent Effie's execution.