The penultimate episode of Downton Abbey pitted the two remaining Grantham sisters against each other once again, with Mary's (Michelle Dockery) claws coming out just in time to ruin Edith's (Laura Carmichael) seemingly happy ending. However, Edith was ready to strike back and finally gave Mary the comeuppance she's had coming for years.

In a sudden turn of events, Bertie's (Harry Hadden-Patton) cousin was killed, making Edith's fiancé the 7th Marquess of Hexham. In other words, if Edith and Bertie were to get married, not only would Edith be filthy rich, but she'd have the highest rank of all the Granthams. That idea does not sit well with Mary, who is still licking her self-inflicted wounds from breaking up with Henry Talbot (Matthew Goode). The only thing standing between Edith and a lifetime of happiness is telling Bertie the truth that Marigold is actually her daughter. Before she has the chance to tell him though, Mary spills the beans over breakfast, leaving Bernie no choice but to end the engagement. The real kicker? He didn't end it because Edith had a child out of wedlock, but because she hadn't trusted him with the news in the first place.

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Of all the treacherous things Mary and Edith have done to each other, this takes the cake as the most awful. Edith once exploited Mary after the incident with the Turk (Theo James) in the series premiere, but the middle sister has been paid back for that tenfold. Edith was left at the altar. She found love with Michael Gregson (Charles Edwards) and had his child, only to learn he was murdered in Germany. Mary mocked her along the entire journey. Now she's lost Bertie, with whom she was genuinely in love before he had money.

The truth is, Mary sabotaged her sister's last chance at happiness because she's unhappy with her own life. She's always been nasty to Edith, and the majority of the time, there isn't a logical reason for it. For several seasons, it's felt like Mary was trying to take down Edith for sport and it's been her most unlikable quality. This wasn't some snarky comment or a practical joke though. She ruined Edith's life purely out of spite and it was disgusting to watch.

Thankfully, brokenhearted Edith has a backbone. She traipses back into the house to pack her bags for London and rightfully informs Mary that she is a "nasty, jealous, scheming bitch." If Mary didn't get the message then, Tom (Allen Leech) made sure it got through her entitled brain that she was choosing to be miserable by being away from Talbot, but that was no excuse to ruin Edith's happiness. Branson has proven himself to be quite an ally since joining the family, but I've never been prouder of him.

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In the end, the incident still served to Mary's benefit. She swallowed her pride and went back to Talbot. Despite all of her arguments, she married him posthaste. Edith, almost always the bigger person, returned to Downton for the ceremony and resigned to letting her and Mary's childhood memories outweigh their mutual distaste for each other.

No one was expecting Mary to end up alone, but it still seems severely unfair that Edith shall have to live the rest of her life alone as a single mother. There's one episode left of Downton Abbey, which means there's still time to do right by her. One can only hope that Mary is truly cognizant of the hurt she's caused and will find something better than an apology to help right the ship. Edith has deserved better for so long.

What did you think of Lady Mary's spiteful move?

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