Mark sat at his favorite table in his favorite restaurant in Cambridge. He loved Henrietta's Table, and his favorite table had window views onto the courtyard. He had been thrilled when Danny and Mike had called and suggested getting together with him in September when they arrived on campus, and he had been thrilled again when they agreed to make their Sunday brunch a regular weekly event. He adored the twins, and he had missed them and their cousins for the past four years. He had made sure to send birthday and Christmas cards and presents to all the kids every year, wanting to make sure that he still loved them, but he hadn't wanted to overstep. He figured he'd let them contact him if they wanted.

He smiled when he saw the boys come in, both wearing their schools' regalia; Danny in a Harvard sweatshirt with jeans and Mike in a MIT sweatshirt with jeans. They greeted him and sat down. They ordered breakfast. Then Danny said, "Grandma wanted us to tell you she sent her regards."

"Really? How did that come up?" He asked. He hadn't heard from Carolyn Shepherd since Derek discovered him in bed with Addison.

"We were talking to Uncle Derek's daughter . . ."

"Derek has a daughter? I thought he and Addison didn't have any children," said Mark, wondering if maybe Addison had lied to him about having an abortion.

"No, Aunt Addie isn't the mother. It's kind of funny; I said to Mike that I would have thought you would be the one to have a surprise baby, not Uncle Derek."

"I get your point, ladies have long been interested in your Uncle Derek." said Mark, with a smile. He agreed that it was surprising that Derek would have a child without being married. "Tell me more."

"Well, you know that Uncle Derek went out to Seattle after you know," said Danny, awkward about mentioning Mark's part in the events that led to his Uncle's move.

"Yes, I know he went to Seattle, and Addison followed."

"Well, apparently he saw an intern there, before Aunt Addie went after him, and she never told him that she was pregnant." said Danny.

"He just learned about the girl last week. It's really very sad," said Mike.

"Why is it sad?"

"She has leukemia."

Mark met Mike's eyes, and he started to feel sick to his stomach. Could the world be that small? "Leukemia?"

"Yea. Someone from the hospital called to ask Uncle Derek to do a bone marrow drive, and it turned out he was a match, so he went out there and learned that the girl was his daughter. I have a photo of them. Do you want to see it?"

"Sure," said Mark. Danny passed over his phone, and Mark's heart ached for his friend as he saw the photo with him and a bald toddler in a hospital gown in a hospital bed. "She definitely has his eyes. What's her name?"

"Chrissy. I think her full name is Christine Shepard."

"Do you know her mother's name?" Mark was anxious to get this information.

"No. But Grandma went out to Seattle to help. She's going to be there for months, I think, although she may come home for Christmas. And Uncle Derek is taking a leave, so he's going to be there for at least three months."

"Well, I'm going to be in Seattle in a few weeks for an engagement party," said Mark. "So maybe I will see them then." He thought that it would be an amazing coincidence if Lexie's niece was Derek's daughter, but he had a sinking feeling she was.

"I think Uncle Derek could use a friend," volunteered Mike. "Mom says he's taking this really hard."

"If Uncle Derek's bone marrow is a good match, does that mean she'll be okay?" asked Danny.

"No," said Mark, knowing that he had to be honest with the boys. "Bone marrow transplants are very risky, even with a good match. The girl is really lucky that Derek's a match; only 1 out of 200 parents will be a bone marrow match. But the doctors have to remove all her bone marrow first, and it takes time for the new marrow to work, and, because bone marrow is needed to fight infection, she can easily get an infection and she won't be able to fight it. There are also other complications. I'm sure she'll get the best possible care, and there's a very good chance for a complete recovery, but there are also big risks."

"You mean she could die," said Danny.

"Yes, she could. But there's a very good chance she will live."

"Aunt Nancy thinks Uncle Derek should get a DNA test, and she might not even be his daughter," said Mike.

"I think Uncle Derek's the best judge of whether a DNA test is necessary," said Mark. "And it sounds like your Grandma agrees."

"So does Mom. She says a perfect HLA test is rare, so it's as good as a DNA test. And Aunt Addie thinks that it's his daughter, too."

"What does Addie say about this?" asked Mark.

"You know she's remarried, right? She told Aunt Nancy to forget the DNA test and to support Uncle Derek, and she told me that the girl's mom is very nice, and that she thought Uncle Derek should have gone after her after they got divorced."

"That's very big of her."

"That's what Mom says, given that the baby was an adulterous love child."

"But Aunt Lizzie says that Aunt Addie cheated first, so we shouldn't blame Uncle Derek. Oops," said Danny, realizing that Uncle Mark was involved in the cheating also.

"Don't worry about me," said Mark. "Addie and I cheated first, before Derek went to Seattle. And anyway, no matter what, it's not the little girl's fault. She's your uncle's daughter, so she's your cousin."

"Yea. She seemed really sweet when we spoke with her. She wanted us to read her a Dr. Seuss book. It must be hard for her; she's been in the hospital for a long time. She said she is excited that she has so many cousins. Danny and I told her that we'd each try and call her once a week."

"That is very nice of you," said Mark. "And I take it your Grandma is making sure all the cousins call."

"Aunt Nancy told Mom that she's not even going to tell her kids about Chrissy unless there's a DNA test."

"That sounds like your Aunt Nancy. I'm glad both of you called her."

Danny decided to switch topics, "So when do we get to meet your fiancée?"

"Next week's brunch, if she is off. It's time for you to meet her," said Mark. He realized that he needed to tell Lexie about Derek and Addison. He didn't want to disillusion her, so he had avoided telling her the story and kept her away from Danny and Mike. But now that her niece was likely Derek's daughter, he needed to tell her.

He waited until after she got off work, and they sat down to dinner; he had made salad, boiled some pasta, and heated up a store-bought sauce. After chatting about her day, he dived right in. "Lexie, what do you know about your niece in Seattle?"

"Not much. I've never met her mother. She's my dad's daughter by his first wife, Ellis Grey, and her name is Meredith. I hope to meet her when we got to Seattle. My mom has been visiting her and her daughter in the hospital every week, and she invited her to our engagement party. She told my mom that she's not up to going to parties."

"I would think it would be weird to meet your half-sister at her engagement party."

"I know."

"Do you know anything about the girl's father?"

"No. My mom hasn't met him yet. I know he's a bone marrow match, and he's agreed to donate. Plus, his mother was a nurse with the Navy, and she's moved to Seattle to help. Her name is Carolyn, and my mom thinks she's great."

Mark smiled. His suspicions had now been confirmed. "Lexie, it's a really small world."

"What do you mean?"

"It turns out that I know your niece's father and his family."

"Seriously? How do you know that?"

"Well, Carolyn Shepherd practically raised me. I was close friends with her son Derek, and I've been an uncle to all her grandchildren. Today I took her grandsons, Mike and Danny, out to brunch this morning, and they told me that she sent her best wishes when they were Skyping with their new cousin, a three year old girl with leukemia who lives in Seattle. Apparently, Derek just learned that he has a daughter, and he's a bone marrow match for her. And his mother's name is Carolyn. So it must be the same child. Do you want to see a photo of Derek and his daughter?"

"Sure. I've never seen a photo of my niece." He showed her the photo. "Your friend is very good looking, and his daughter looks very sick. She does seem to have his blue eyes. I can't believe you know my niece's father. If you're so close, I'm surprised he didn't tell you."

"Well, that's another story. Like I've told you before, I was a manwhore before I met you. But Derek, his wife, and I were close friends until over four years ago. Derek had started working very hard and ignoring his wife, so Addison and I fell in love, and Derek walked in on us making love. He immediately left for Seattle, where he met your sister. Addie left me and went after Derek, and I left for Boston. Derek and Addie then moved back to New York, and they were divorced over a year ago. But I haven't spoken to Derek since he found Addie and me together, more than four years ago."

"So Derek is single now?"

"Yes, he's single."

"So maybe he and my sister will have a chance. When I spoke to her, I got the feeling that she really loved him. But Mark, what are you going to do now?"

"Well, we're going to get married, at least as long as you're not disgusted with me now."

"I still love you Mark. I don't care about your past; I only care about your present and your future."

"So Chrissy is going to be both my niece and Derek's daughter. I'm going to have to reach out to Derek. From what the boys said, I think he's going to be in NY this week, getting ready to take a leave of absence, so I'll take the train on Tuesday and take him out to dinner."

"Sounds like a good plan. I'd hate for you to meet for the first time in a long time at the hospital."

So Tuesday found Mark in New York. He arrived at Mount Sinai at 4:30 p.m. and went straight to the o.r. board. He saw that Derek would be in surgery until 7 p.m. at least and that Addie was in surgery until 6 p.m. So he decided to go for a walk and come back at 6:30 p.m. He figured that it made sense to talk to Addie first. When he came back, he saw that Derek's surgery was still going on, but Addie's was over, so he went to her office and knocked.

Addie was shocked to see Mark. "Mark, what are you doing here?"

"Congratulations, Addie, I heard you got married." Mark said to start. "It's kind of a funny story, but I'm here to see Derek. I know he needs a friend, and I want to be his friend again."

"What makes the story funny?"

"Well, I learned that he has a daughter in Seattle."

"I know."

"And I'm engaged to her aunt, so I'm going to be his daughter's uncle."

"You're engaged?" Addie said, shocked.

"Yes, to Lexie Grey, Meredith Grey's half-sister."

"Well, I performed surgery on Molly Grey and delivered her daughter, Laura, who is Lexie's niece."

"What a small world it is. Do you think Derek will forgive me?"

"He has forgiven me, and I'm the one who took the marriage vows."

"I hope so. I'm hoping to take him to dinner tonight."

"Good luck, Mark."

"Thanks."

Mark decided to sit down outside Derek's office and wait for him. He figured that Derek would talk to the patient's family after the surgery. Soon he heard footsteps, so he stood up and saw Derek approach. His friend looked much more than four years older.

"Mark, what are you doing here?" asked Derek, shocked to see his former friend outside his office. The last time he saw Mark he was in bed with his wife. He hadn't expected to ever see Mark again, much less to have Mark come looking for him.

"I've come to take you out to dinner."

"Mark, I have a lot of work to do," said Derek, puzzled about why Mark had suddenly shown up and wanted to eat with him.

"I know, but I have a story to tell you."

"Seriously?"

"Believe me, Derek, it's a story you'll want to hear before you go back to Seattle."

"You know I'm going to Seattle?"

"Yea, I took Danny and Mike out to brunch on Sunday. But let's go into it at dinner. My treat."

Derek looked at Mark, and he remembered that he'd forgiven Addie, so he might as well take this olive branch that Mark had offered. He could really use a friend.

After they ordered their dinner, Derek looked at Mark. "So you have a story for me."

"I do. So I moved to Boston four years ago, and I met a sweet, funny, lovely intern."

"That sounds familiar," said Derek with a smile.

"Oh, you won't believe how familiar," said Mark with a laugh. "Her name is Lexie Grey, her half-sister is Meredith Grey, and your daughter is her niece."

"Are you serious?" Derek was astounded.

"Yes, and your mom knows. She told Danny and Mike to give me her regards. Lexie had spoken to Meredith about us visiting her niece at the hospital, and I think your mom thought it would be best if I didn't surprise you there. So I thought I'd come to town and take you out to dinner and let you know that we're going to be related soon."

Derek nodded his agreement. "I'm glad you came to tell me. It would have been a shock seeing you in the hospital."

"I was afraid you might punch me. I thought you might still be mad at me."

"It has been four years."

"I hope you don't mind if I go with Lexie to see Chrissy. She has never met Meredith or Chrissy before, and she wanted my company.

Derek looked into Mark's eyes. "You're serious?"

"Lexie and I are engaged. Chrissy is going to be my niece. And you know how much I love being Uncle Mark."

"The kids all love you. They've missed you."

"I loved being part of the Shepard family. I shouldn't have gone after Addie."

"Maybe it all worked out for the best," Derek said with a smile. "Addie's happy with Jake, and you seem to be happy with Lexie, and I have a wonderful daughter."

"Lexie thinks Meredith loves you," Mark volunteered.

"But she hardly knows Meredith," said Derek. "I may have blown my chance with Meredith."

"Well, you're going to be spending a lot of time in Seattle with her, right?"

"Yes, with our sick daughter. Meredith has no interest in me now; her whole focus is on Chrissy."

"When Chrissy is better, you'll have plenty of time to court Meredith."

"That's nice of you to say 'when.'"

"Derek, I hear you're bone marrow is a match, so that's good news."

"Yes, but you know a bone marrow transplant is risky."

"Yes, but there's a lot of hope. I'll do anything I can to help."

Derek looked Mark in the eyes and saw his friend was serious. "There is one thing, but it's really for Lexie, not you."

"What is it?"

"My mom has been telling Chrissy lots of stories of me as a little boy. She loves the stories. And she wants to hear stories about her mom as a little girl. Meredith's mom is dead. Richard Webber has had a few stories to tell, from working with Meredith's mom." He looked Mark in the eyes again. "Lexie's mom, Susan, comes to visit every week, but she didn't know Meredith as a little girl. It would mean a lot to Meredith if her father could visit Chrissy and tell her some stories about Meredith as a little girl."

"I'll see what I can do, Derek. I can certainly tell Chrissy some stories about you as a little boy."

Derek laughed, "Would I like the stories you'd tell?"

"Don't worry, Derek, I'm a good uncle. I'd only tell her good stories, stories that will make her smile or laugh," Mark said with a smile. "At least now. When she's a teen-ager, I'll tell her stories about boys like me, so she knows how to protect herself."

"You've always been a great uncle, Mark," said Derek. "I'm glad that you'll be Chrissy's uncle. When is the wedding?"

"We don't have a date yet. I'd like you to be the best man and Chrissy to be a flower girl."

"I'm sure she'd love to be a flower girls. Girls always like that kind of stuff. But it will be a long time before she can be out in public. And you'd have to ask all the cousins to participate."

"We'll see. We could do special small ceremony just with you and Meredith and Chrissy."

"But first she needs to get out of the hospital," said Derek.

"I know she has a tough battle ahead, but Lexie and I will be with you every step of the way. And I know you have your mom and the whole Shepard contingent, except maybe Nancy."

"I take it the boys told you about Nancy and her insistence on the DNA test," said Derek. Mark nodded. "Thanks to Meredith and Mom, that problem is over, and Nancy and her family are onboard now."

"What happened?"

"I'm still mad at her. Nancy had the nerve to call Meredith directly and ask her to do a DNA test with Mom and Chrissy even though I told her no DNA test was needed. She told her that she wouldn't let her kids call Chrissy unless she had a positive DNA. And Meredith agreed to do the test without talking to me. I would have told her no, but Meredith wanted Chrissy to get calls from Nancy's kids. And, as we all knew, the DNA test showed that Chrissy was mom's granddaughter. So I got a text from Nancy." He took out his phone to read it to Mark, "Congrats, Derek. I'm sorry I doubted you. To atone, I've donated $20,000 to the Pediatric Cancer Foundation in Chrissy's name. My kids will be calling Chrissy every week. Please let me know if there's anything else I can do."

"What did Meredith say?"

"She said it was nice she made the donation, but she still thinks Nancy's a bitch."

"I agree with that."

"Me, too. Fortunately, Nancy just sent the text and hasn't tried to see me. I'm not planning on seeing her for a long time."

"Did you reply to Nancy's text?"

"Just to thank her for the donation. More funding is needed for pediatric cancer research, so her gift will do some good. But right now I can't forgive her for hassling Meredith."

"Can you forgive me?"

Derek met Mark's eyes. "I forgave Addie, so I can forgive you. Besides, you're going to be Chrissy's uncle. And I would never have met Meredith if it weren't for you, so Chrissy is alive because of you."

"That's nice for you to say."

"It's true. And I really need a friend now. I'm very worried. We have another meeting with Chrissy's doctor this week, and I'm hoping that she will be in remission."

"I hope so, too, but if she's not, they'll figure some other medication combo."

"Mark, you and I both know there's a limit to the medication combos to fight leukemia. They've tried a lot of combos so far. And she's lost a lot of weight. I don't know if she can take much more."

Mark put his hands on Derek's, and said, "I think Chrissy must be tough, being your daughter and Meredith's."

"Mark, you've never met Meredith."

"But I met her Mom when I interned at the World Health Organization my junior year in college. And she was very tough. She had to be to get ahead as a woman surgeon then, particularly at her level. I'm sure her daughter must be very tough. And you're tough. After your dad died, you helped your mom raise your sisters."

"Thanks, Mark, but Chrissy's only a baby."

"But I can see from the photo that she's tough. She's smiling despite being in the hospital, having lost her hair."