We saw Maggie pressing forward toward the next surgery and the next one after that in a frenzied effort to cure her mother Diane. Many of her fellow surgeons cycled through to give their expert opinions and to support their coworker / friend / sister and her mother. The emotional dynamic between the two women was challenging to witness after having watched them fuss and fight with each other for a couple of previous episodes. Maggie's rapid-fire responses seemed all about compartmentalizing the daughter in her so as to bring forward the doctor in her so as to find a way to increase her mother's chances for survival. We were also reminded that Meredith is Maggie's sister and Richard is her biological father as we saw both people trying to talk compassionate sense to Maggie about her mother's course of treatment.
What started as breast cancer began spiking elsewhere in her body, first in some cells around her original incision which put Nathan in the operating room and in contact with Meredith. The romantic tension continued between them even as both were exhausted by trying the very personal medical case in front of them. When the cancer moved into Diane's liver, Meredith voiced objections to rushing into the next surgery. Soon after Diane, with Maggie's urging her on, fired Meredith, though it was probably for the best given that Meredith and Maggie seemed to learn something about themselves and each other from interacting as strictly sisters for most of this hour.
We soon saw Maggie concocting a surgical dream team: Jackson, Diane's original Seattle surgeon, as well as Richard and Miranda. Yep - the trouble twins who have been on the outs since Miranda brought Eliza to the hospital to shape up the surgical residency program which put Richard out of a job. As any viewer would expect, Richard and Miranda had an aversion to working together to get Diane into an aggressive clinical trial even as they shared a similar point of view on her best medical chances.
It soon became evident that Maggie was letting her concern for her mother, and her guilt over fighting with her while she was unaware of her mother's condition, shoot her into overdrive as a way to fix this very scary problem going on in her family. She maintained a stiff smile on her face at all times, trying to convince herself, her mother, and everyone else that there was no way to go except forward at 100 miles per hour. Diane tried to keep up, though she looked ever more exhausted as each hurdle presented itself.
Miranda kindly and firmly explained all of the possible side effects of the trial to Diane and then we saw them all become reality in a montage which showed the rest of the surgeons, including Owen, taking turns treating Diane, both at home and at the hospital. We got a rare moment of lightness as she insisted Maggie learn how to make her lasagna, including noodles from scratch. The resulting dinner party brought back some of Grey's history as Diane asked if she could pay respects to Ellis - Maggie's biological mother, considering she was staying in her house with her daughter's family. A moment of hilarity ensued as they all laughed at the absurdity of Ellis's final resting place - the scrub sink in OR 2 - which was, as Meredith pointed out, her favorite operating room. The moment turned grey as Diane laughter turned to coughing up blood, which we soon learned was caused by an esophageal tear.
As the next surgery loomed we got further scenes of conflict - Meredith urged care in Diane's surgical plan and Maggie blew up at her before running from the room. A rare moment of vulnerability swept across Meredith's face which she carefully brushed aside in the face of Nathan's concern for her well being. We next saw Richard trying to coax Diane to be honest with him about whether she was up to the next round of treatment. In this scene between two of Maggie's parents we learned a bit more about Diane's concerns for her daughter, that she will need to know she did everything she could for her mother before she dies.
Inevitably, Diane's health began to deteriorate to the point at which she asked Maggie to let her go. Maggie tried to support her mother, but spun out once she was out of the room. She allowed Nathan to comfort her with a listening ear and a kind hug before she was ready to sit with her sisters - Meredith and Amelia - and accept that she had to make the absolute most of the time that remained for her with her mother. At least Diane got in some good motherly advice about taking a bite out of life rather than living inside the lines before we had to say goodbye to this vibrant character.
One win we got out of this tumultuous hour of television was a full circle moment for Richard as Miranda found him sitting quietly in an OR gallery after Diane's death. He'd bowed out after bring Maggie's father to town to help her figure out how to mourn her mother. As Miranda slid into the seat next to Richard we heard him seemingly let go of Ellis, the woman he loved who never forgave him. It did this viewer's heart good to hear him tell Miranda that he didn't want to make the same sort of mistake in his friendship / mentorship with her. Unfortunately, we also got a loss as Meredith put yet another barrier in the way of moving forward with a relationship with Nathan, citing the loss that Maggie had suffered and how she would need to be there for her. It remained unclear whether or not Nathan was indeed as understanding as he seemed to be in assuring Meredith he heard what she was saying. And okay, we got another win as we saw Meredith have a sort of full circle moment with Ellis too. It was very simple and not fussy as we heard Meredith's voice say 'Goodbye mom' over a scene of her and Amelia joining Maggie to eat the last of the pan of her mom's lasagna.