A/N: As always, thank you for your patience with these chapters! This one's a big one for Meredith and Maggie, one of several major plot lines I want to work through in the next couple of chapters. I hope you enjoy it!

Two weeks later, Meredith was staring intently at the computer screen in her office, putting the final touches on her second grant proposal of the month. Leaning back in her chair slightly, she stared at the header on the screen, still finding it slightly odd to see the words 'Seattle Presbyterian Health System' below her name and title. She was just about to hit the print button when a knock on the door broke her concentration.

"Come in!" she called out, fully expecting the door to open and Nathan or Molly, or perhaps Dr. McLaughlin, to walk in. Instead, she looked up to find one of the last people she'd expected to see that day standing in her office door.

"Diane?" she said in confusion, as though not believing her own eyes.

"Hello Meredith," Diane Pierce said calmly, stepping into the office and closing the door behind her. "I hope you don't mind me dropping by unannounced."

"Of course not," Meredith said, quickly collecting herself. "Please, come in, have a seat."

"Thank you," Diane said, taking a seat on the small couch. "I imagine you're wondering why I'm here."

"You could say that, yes," Meredith said. "Not that I'm not happy to see you, of course. Does Maggie know you're here?"

"If by here, you mean in Seattle, then yes," Diane said. "But if by here, you mean, sitting in your office, then no, Maggie does not know that I'm here. She thinks I went to the Space Needle this afternoon while she's at work."

Meredith sighed. "Diane, I don't know if she's said anything to you, but I feel like I should warn you, she probably isn't going to be happy that you're here."

"Oh, she's going to be furious," Diane said.

"So she did tell you?"

"She said you'd had a fight," Diane said. "She wasn't terribly specific on the details, but I know it was bad if she felt that it was enough to warrant moving out of your house. I'm sure when she hears that I came to see you, I'll hear all about how I'm meddling, how I need to treat her like an adult, how I need to let her sort out her own problems."

"She won't be wrong on that," Meredith said.

Diane sighed and nodded. "Meredith, if this were just a regular visit to my daughter, I wouldn't be here," she said. "But I know Maggie, and I know if I leave this up to the two of you, it will be a very long time before you two sort this out. I suspect her stubborn streak was something she inherited from your mother."

Meredith smiled knowingly. "We both did," she said.

"Yes, well, that's why I have to meddle," Diane said. "Meredith, I don't have time to wait for the two of you to sort this out."

"Diane, what's going on?" Meredith asked.

"Maggie is going to need your support very soon," she said. "I need to know that she'll have it, and I don't have time for the two of you to drag your feet. Meredith, I'm dying."

"Diane…"

"I have metastatic breast cancer," Diane continued. "I've seen a half dozen specialists already. They all tell me the same thing. There's nothing left to do, surgery, chemo, radiation…none of it will cure me. I'm going to die."

"Diane, I don't know what to say," Meredith said.

"I've had time to come to terms with it," Diane said. "And I think I'm at peace with dying, mostly, except I'm terrified of how this will affect Maggie. She's never had to deal with anything like this before."

"Diane, you don't have to worry about Maggie," Meredith assured her. "No matter what argument we're having, she's my sister, and I will always be there for her."

"She needs to know that, Meredith," Diane said. "She won't reach out if she doesn't."

"We're sisters," Meredith said. "Of course she knows that I'll be there for her."

Diane shook her head. "No, she doesn't," she said. "Meredith, this is all new for her, remember? She never even had any close friends before she came to Seattle. She was always so advanced academically and then professionally, she's never been on the same wavelength as her peers. You, Alex, Amelia…this is entirely new to Maggie."

"Alright," Meredith said. "I'll talk to her."

"Mom, seriously, you don't have to cook every night that you're here," Maggie said, frowning as she looked around the kitchen that evening. "And where did all this stuff come from? I don't even recognize half these pots and pans."

"That's because I just bought them today," Diane said. "You're going to have a grown-up kitchen by the time I'm done here."

"Mom…" Maggie paused at the sound of a knock on the apartment door.

"Well, don't just stand there," Diane said. "Go answer the door."

Shaking her head, Maggie was still smiling at her mother's antics when she pulled open the door to find herself face to face with her sister.

"Hi," Meredith said.

"What are you doing here?" Maggie asked. "Now's not a good time."

"Margaret, don't be rude, let your sister in," Diane called out from the kitchen.

"How did you know Meredith was at the door?" Maggie asked, stepping back to let her in.

"I'm the one who invited her, that's how," Diane said, stepping out of the kitchen and picking up her coat off the back of the couch. "You two need to talk."

"Mom!" Maggie exclaimed. "You have got to stop meddling in my life! I am perfectly capable…"

"Maggie, you and Meredith have had plenty of time to sort this out on your own," Diane said, putting on her coat as stepped past Meredith toward the door. "Now I'm pulling rank. Dinner is in the oven and I'm going for a walk, you've got forty minutes until the timer goes off. I suggest you start talking."

Maggie shook her head as Diane shut the front door behind her.

"She treats me like a child," she sighed.

"She loves you," Meredith said. "Sometimes I wish I'd had a parent who cared enough to meddle."

"The grass is always greener, I guess," Maggie said, sticking her hands in her pocket nervously as an awkward silence descended on the two of them. "So…I guess we should talk. She's going to expect a report when she gets back."

Meredith laughed and nodded. "Do you want to start?"

"At this point, I just want to know why, Meredith," Maggie said. "Why did you feel like you couldn't talk to me?"

"About the job, or about Nathan?" Meredith asked.

Maggie hesitated. "Both, I guess," she said. "When I told you I liked Nathan, why didn't you say anything then?"

"Well, for one thing, you told me while we were standing at the altar at Amelia's wedding," Meredith said. "It wasn't exactly a good time for a heart to heart."

"Meredith…"

"Fine," Meredith sighed. "There was nothing to tell at that point. Yes, I'd slept with him, but that was it. We weren't seeing each other, there was no relationship there. It was just one night."

"Except it wasn't," Maggie said. "Clearly it was more, it was always more than that. You should have said something, Meredith."

"Saying something would have meant acknowledging that," Meredith said. "Don't you get it, Maggie? I wasn't ready to admit that I was even thinking about a relationship with someone other than Derek. Did I have feelings for Nathan, even then? Yeah, probably, but I wasn't even going to admit that to myself, let alone anyone else."

"You still should have said something," Maggie insisted. "Maybe not right there at the altar, but the next day maybe. Just a simple heads' up, a 'hey Maggie, you know that guy you're interested in? I already did him' would have been nice so I didn't make a fool of myself like I did."

Meredith nodded. "You're right," she said. "I should have told you what happened between us, even if I didn't know what it meant. I'm sorry that I didn't, and I'm sorry that you got hurt in the process."

"Thank you," Maggie said. "And the job?"

"I'm not going to apologize for taking a new job, Maggie," Meredith said. "That was something that I had to do, for me."

"I'm not mad that you took a new job," Maggie said. "I'm hurt that you didn't talk to me about it first. I'm your sister, Meredith, we're supposed to talk about these things."

Meredith shook her head. "I think that's the problem, Maggie," she said. "Neither of us grew up with a sister, and we have very different ideas about what having one actually means."

"What do you mean?"

"Do you Amelia is a good sister?" Meredith asked.

"Of course," Maggie said.

"Amelia quit her job in Los Angeles and came to Seattle without telling anyone," Meredith said. "Including Derek, whose doorstep she turned up on one morning expecting a place to stay. I'd say that's a bigger life decision than taking a new job across town."

"Right, but that's Amelia," Maggie said. "And I'd be upset if she did that now without talking to me."

"Maggie, I don't know what it means to you, but being a sister to me is not about sharing every little thought," Meredith said. "Maybe if we'd grown up together it would have been different, I don't know. But that's not who I am, and it's not who I'm ever going to be."

"So you don't want to be a sister," Maggie said.

"That's not what I said, Maggie," Meredith insisted. "If by sister, you're looking for someone who's going to stay up until two in the morning talking about dreams and plans for the future, then no, that's not what I'm ever going to do. But that doesn't mean I don't care. You're my sister, Maggie, and that does mean something to me, even if it's not the same thing it means to you."

"What does it mean to you?" Maggie asked.

"It means I've got your back," Meredith said. "When you need me, I'm your person. I'll drive the getaway car. I'll kick your butt when you're being your own worst enemy. When you need a shoulder to cry on, I'm there. You're not ever on your own again, Maggie, not so long as I'm around."

Maggie shook her head, sniffing back tears. "You mean it?" she asked.

"Of course I mean it," Meredith said.

"I guess maybe I overreacted a little," Maggie admitted. "I'm sorry I moved out without talking to you."

"Did you want to move back in?" Meredith asked.

"I signed a six month lease," Maggie said, looking around the sparsely furnished apartment.

"Then I guess we're going to need to get you some furniture," Meredith said. "Where do even sit down to eat dinner?"

"At the counter," Maggie said, nodding toward the small granite peninsula separating the empty dining area from the kitchen. "My mom bought the barstools yesterday."

"Maggie…"

"It's pathetic, I know," Maggie said. "Do you want to stay for dinner? It's not lasagna, but anything my mom makes is amazing."

"I would, but I can't tonight," Meredith said, forcing herself to mask the sadness she felt knowing what was coming when Maggie and her mother sat down to talk after dinner. "But I'll be around after dinner…you know, if you want to talk or something."

Maggie laughed, having no way of knowing that Meredith wasn't joking. "Right," she said. "I'll keep that in mind."