Yay! Edmund is free of Mary, and it is by his own choice and action. I also like that the final straw was not Henry, but Mary's own character, her heartless greed. I'm obviously not happy about the pain Edmund is suffering in the process, but I am glad that he knows the full truth about her. Delusions would only make his heart cling more strongly to her in the long run.
It really says something about Mary's depravity that Edmund is relieved to find someone who agrees with him that adultery is wrong. After all the compromises he made in canon for Mary's sake, I've really enjoyed the theme in this story of the similarity of heart and principle between him and Fanny. Their selfless caring for each other is in such stark contrast to the grasping "love" of Henry and Mary.
Mary's response as revealed in her letter is so sad. With Henry, I feel at least that he is truly trying to change but is struggling with his old nature; Mary, on the other hand, is still firmly entrenched in her worldview and values. Not even the pain of losing a man she cared for can make her reconsider. I hope she is reflecting more than indicated by her letter, that she is just putting up a front for her brother.
I don't have an issue with Fanny showing Mary's letter to Edmund. I think I would have, had she done so earlier in the story when she was contemplating it. It would have seemed like a desperate effort, and honest as she is, I think she would have always felt some guilt over whether revealing the letter was a selfish act. Here it is an act of mercy.
