I have a theory about Edith and if you rewatch the last season, you may see what I saw. Look away quickly if you don't want to read a potential spoiler. Edith has always been the odd one out in the series and there's something about her that's quite sad like she's been treated differently. When Edith became pregnant, Robert's younger sister, Rosamund, was so generous in offering to pay for her trip to Switzerland and to say it was a holiday where she needed Edith's assistance and that they both wanted to learn another language. Of course, she had the baby abroad and he was adopted out so no one was the wiser. When Edith is upset while visiting Rosamund at her London home, she says to her, I'm paraphrasing here as I don't remember the exact quote, "You don't know what it's like. You've never been a mother." Rosamund looked taken aback by the comment. Her face tensed and her there was something in her eyes and it gave me the impression that she had been. Then I started to wonder, if she had been, had hers been adopted out, as well? The more I thought, the more I realized that, like Edith, Rosamund has red hair, while no one else in the immediate family does. (I know, her mother-in-law, played marvelously by Shirley MacClaine does but stick with me here.) Could it be that Edith is Rosamund's child? That like Edith, Rosamund has been in love (or been feisty and impetuous like Rose) and had become pregnant out of wedlock, which was a huge scandal in that era, and that Cora and Rosamund had taken a holiday together and when the baby was born, Robert and Cora took her in as their own and that it was Edith!!? That could be why she never seems to fit in and has such animosity towards Mary. Carson and Mrs Hughes would never tell a soul as they are so devoted to the family and highly revered for their discretion. It's an interesting plot line to consider. I'm really looking forward to season five to find out if there is anything to my theory or if my imagination has just run wild. What do you think?