Hey guys! Thanks for the reviews, here's the next part.

BTW, the disclaimer ALWAYS applies.

Chapter V

"Are we still breathing?" Derek asked, giving Addison a side glance as he drove her car to the hospital. It was Addison's first day back at the hospital after Mark's death and she was doing her best to hide her nervousness. Still, he knew her. He knew what the little signs meant: she was twisting a curl of red hair in her finger, she was biting her lower lip and she kept looking at the window, then straight to the road in front of her and again through the window.

Addison was freaking out.

"Trying." She meant it as a joke, but Derek didn't miss the fear behind her voice.

"Everything's going to be okay, Addie. Everyone at the hospital loves you, you have tone of friends and they just want you to be alright."

"That's the thing Derek! I don't think I can take everyone being all worried and asking me if I'm okay, or giving me the pity looks…"

"Nobody is going to give you pity looks…"

"Seriously? Derek, my husband just died leaving me pregnant! I'm a freaking pity-case poster over here!"

"Okay, maybe some people are going to give you pity looks and ask dumb questions, but your friends…" he was interrupted mid-sentence as his cell phone started ringing. He sighed, "Hold on, Addie."

"Okay."

"Derek Shepherd. Hey.", pause, "Yeah, sorry, I couldn't make it home.", really long pause, "I know. It was late and…", sigh and another pause, "I'm on my way to the hospital.", pause, "Addison.", wince and pause, "I'm giving her a ride, since we both had to come to hospital this morning…", pause, "No… look… Mer… I just… you know what? Talk to you at the hospital. Bye." And Derek flipped his cell phone close.

"Oh my, God. Derek, did you just hang up on Meredith?"

"No."

"Derek?"

"A little bit, yes."

"Derek!"

"I'm sorry, I'm sleepy okay? I don't do well with girl flip-out so early on the morning."

"Don't I feel safe you're driving, then." Addison muttered, "Derek… look… my life is messed up right now, I don't want you to drag you into this…"

"You're not dragging me into anything Addison."

"Come on, I was sitting right here, listening while you got into a fight with Meredith over staying over at my place."

"She's just being whiny, not big deal. She'll be over it."

"Derek… I do appreciate you taking care of me and Matt, but we're not your responsibility. You're with Meredith now and you owe it to her to be one hundred percent involve into your relationship. Yet, you're here, worrying about your pregnant ex-wife…"

"Addie…"

"You don't have to. Seriously. I won't let you screw up your life for me on some misguided idea that you need to play the knight in shining armor, I can take care of myself and my son."

"Addison." He sighed and cut off the engine of the car. Only then did she noticed that they were already at Seattle Grace. Instead of descending from the car, Derek turned to face her and took her hand in his, "Addison." He whispered this time, coaxing her to look at him. When she finally met his eyes he continued talking, "Meredith and I are alright. I promise, you won't mess us up."

"But…"

"Hey, Montgomery! I'm talking now, alright?" he smiled at her, unable to resist moving a lock of her that kept falling over her eyes behind her ear, "What both you and Meredith need to understand here is that you and I are family. I've known you for a third of my life, I love you, you were my wife. My wife, Addison! That implies really strong feelings and a whole lot of history. That doesn't go away. And after everything we suffered together, we have just started making repairs. We are finally back at a place where we can be friends and care about each other. And whether you want to admit it or not, you need help right now, Addison."

"Derek…"

"No! Come on! You let the chief help you! Bailey, Izzie, Torres, Karev, Preston… why can't I help you? I want to help you, not because I pity you but because I love you. Because you're my friend and Mark was… he was like a brother to me for almost my whole life and he was my friend again when he… and he would never want for you to be alone."

"You can't assume this responsibility for me Derek. You can't be the guy that stands by my side during this."

"Why not?"

"Because… you have your own life. And mine was with Mark. Mark and I were supposed to raise our son together, but then he died. So, now I have to do this on my own."

"I'm not trying to replace Mark, Addie." He said softly, not missing the tears she was trying to hold back clouding her eyes, "I'm trying to be your friend, and Mark's too. This is going to be hard and you know it. You're mourning and you're pregnant. At some point you'll want to talk about Mark, and I have known him all my life, so I'm your guy. You'll want to buy ridiculously expensive and cute baby clothes, and I already now how freaky you get when you're in a shopping spree so you won't frighten me. Or you'll get disgustingly sick or ache in funny places, and I already know your anatomy from hair to toe, so you don't have to be embarrassed to talk to me about it." He paused, watching as she laughed a little at his list of reasons she should let him help. He sent a quick thank you to whoever was watching that he had managed to make her laugh today.

"Derek, you're sweet but…

"No. I'm being a good friend, an excellent ex-husband and the best uncle ever."

"Uncle, uh?"

"Come on, Matt is going to need a silly uncle. Roan is always traveling and Jimmy lives in New York, so I'm rather geographically convenient."

Addison, smiled one last time before getting serious and facing Derek again.

"Look… I just… I get that you want to help me out, but about the baby… I don't want this to be hard for you…"

"I'm okay."

"Derek, come on."

"I'm okay. Promise. At first it was kinda hard… but this baby is really important in your life, and it's the last piece of Mark we have to hold on to. So… I'm asking you to let me help you out and to let me… be a part… a part of Matt's life. If that's okay." He added the last part shyly, hoping she would know he was saying it from the heart. He got that she was probably worried about replacing Mark in her baby's life, but he was already involved in this. Since Addison told him she was pregnant and he had his conversation with Mark, he felt he was already invested in Matt Sloan's future.

Addison didn't answer right away and that was making him nervous. He was starting to wonder if maybe he had pushed to far, asking her to let him be an active part of her son's life when she was barely into her first trimester. When her husband had just died. Maybe she wasn't ready to open more spaces of her life… maybe she just felt she couldn't trust him anymore after all they had gone through together.

He waited for a couple of minutes as Addison got her thoughts together. Finally, her deep blue-green eyes were staring right through his soul.

"You're going to be a great uncle."

"Really?" he asked, a smile spreading on his face.

"But I have rules."

"You have rules?"

"Yes. Important rules."

"Let's hear them, then." He answered, amused.

"First, you never ever let me and Matt interfere with your life and Meredith's."

"You won't."

"Second," she ignored him, "you don't get to start acting like I need help to walk on my own two feet. I'm pregnant, not sick. You get to help me but you don't get to order me around or over-protect me."

"I see how that one could be tricky."

"Third, you're not obliged to anything. If you don't want to do this anymore, if you change your mind, just tell me."

"I won't change my…"

"I'm not done with rule number three. You get to change your mind, but please, and this is really important, I need you to do it before Matt is born. Just… if you change your mind and don't want to be this involved with us, do it before Matt gets attached to you. He has already lost so much and he's not even born yet, I don't want him to get used to having Uncle Derek around and then lose you too."

"He won't. I already love him, I promise."

"I know you do." She caressed his cheek lovingly, "Finally, rule the fourth. You gotta tell Meredith."

"What?"

"You gotta tell her, Derek. She has a vote here, you're her boyfriend, I can't accept your help if you don't tell her that you want to be a part of our lives."

"Addie…"

"I won't do this to her. So, the ball is in your court Derek. I'm really grateful you're even offering to be with me during this, but your girlfriend doesn't deserve to not know about this arrangement. So, I'd love for you to be Uncle Derek, but only if you promise to tell her."

Derek smiled at her, thinking for a few moments.

"I promise." He finally said. She smiled at him, a couple of tears escaping from her eyes. She threw her arms around his shoulders and he leaned into her as they embraced.

"Thank you." She whispered in his ear.

Neither of them noticed as one Doctor Meredith Grey stood on the parking lot, watching them closely through the car's window.

"It's good to have you back." Richard Webber smiled at his old student, sitting in front of his desk with a nervous smile on her face.

"It's good to be back."

"Addie," he stared at her long in the eyes, but she didn't bulge or offered any information, so he continued, "if you ever need to talk…"

"I'm fine, Richard."

"No you're not. But that's okay, you don't have to talk yet if you're not ready. What you DO have to do is take it slowly. Izzie Stevens has done a decent job of keeping track on your patients, you have top nurses and doctors on your teams, you can take it easy."

"I'd rather be in the hospital that hanging at my place, Richard."

"I know, but you need to rest. Even if you'd prefer to hang out here, you need to sleep and eat proper meals at decent hours. Also, I want your OB's assurance that you're doing alright and my future grandchild is healthy and happy in there."

Addison couldn't help but smile at his sweet words, allowing him to take both her hands into his.

"Okay… you know… this whole thing… the one bright side is that I have realized for the first time that Matt and I have more people that love us than I thought. Thank you, Richard. You're going to be a great grandfather."

"And you're going to be a great mom. Not get you butt of my office and save some lives." Addison smiled as she left the chief of surgery's office. Maybe today wasn't going to be such a bad day after all.

"Derek!" Meredith Grey ran after her boyfriend as she saw him turn in a corner, busy checking some charts. He had spent the night at Addison's, so she hadn't had a chance to talk to him yet. Derek stopped, turning lazily to face her and then giving her his patented 'McDreamy smile'.

"Hello, Meredith. How are you?" he tried a casual approach, kissing her softly on the cheek. Maybe if he played it cool she wouldn't be so upset…

"Derek! Hello? Seriously?!" okay, scratch that.

"I'm sorry, Meredith. I just… lost track of time, and then Addie was asleep and it was so late…"

"So, you just spent the night at your ex-wife's place, alone, and I'm supposed to just stand here and do nothing about it?"

"It's not like that, Meredith. Come on, even you were worried when she stopped taking calls. I just wanted to make sure she was okay. I told you I was going over to Addison's…"

"You failed to mention the fact that you were spending the night."

"I didn't plan to spend the night. Look… I need you to understand Meredith. Addison is… she's family. Right now she needs her family…"

"No! Derek, come on!" Meredith stared in disbelief at him. How could he not understand? Of course she was worried about Addison. Doctor Montgomery-Sloan, formerly Montgomery-Shepherd, had never been anything but kind towards her. Meredith never wished her bad and sometimes she even considered her a friend, albeit not a close one. But where Addison and Derek were concerned, she was not so sure about them. This was not a year and a half ago. A year and a half ago, Derek and Addison were barely in speaking terms after the divorce. A year and a half ago, Derek was fine with Addison out of his life; he didn't need Addison in his life. He had her. Meredith. They were finally getting their chance, they could finally try and be a normal couple, be in love, build a life together.

Then Addison and Mark had gotten married. She knew it was the turning point. Derek had been a changed man from the moment he got and invitation to Addison Montgomery and Mark Sloan's wedding. He had been happy and carefree, they both were happy and carefree. But then, he had gone back to 'Dark Derek'. Moody, pained, with a face of constant agony.

"Meredith?" Derek entered their shared bedroom at Meredith's mothers' house. It was just more comfortable stating there than at the trailer.

"Yeah?" Meredith had been sitting on her bed, reading through some medical journals. When she lifted her face she was met with a rather surprising sight.

Derek was wearing a tuxedo.

"You need to get ready." He announced. She didn't even need to ask him what he was talking about. There was only one event that could have him this riled up. Mark and Addison were getting married that day. She knew it, she was invited too. Never be said Addison was anything but polite. But Derek had been so put off by the wedding she figured they were just not going.

"Derek, are you sure? I mean, this is Addison. This is Addison's wedding to Mark, the best friend from hell. Remember that? They cheated on you?"

"Yes, Mer, thank you for that lovely trip down memory lane. Now, can you please get dressed so we can go?"

"Seriously?" she asked slowly, but complied by standing up and looking for a suitable dress in her closet.

"Seriously."

"I don't understand." She commented, turning to face him with a beautiful purple gown in her arms, "You hardly ever talk to Addison and you hate Mark. Why do you…?"

"Because," he walked towards her and kissed her softly on the forehead, "I hardly ever talk to Addison and I hate Mark. That's why we are going."

"I still don't understand." She commented, while entering the bathroom to get dressed and her make up on, but leaving the door opened so they could continue their conversation.

"I think... we are in a good place Meredith. You and I, we're on a good place. I think I'm finally ready to let everything go, you know? Addison and Mark were once the biggest part of my universe. Now, I have to play it cool whenever I see Addison down the hall, and I have to worry about this being the time when Mark and I are going to get into this huge fight. I'm over that. I'm happy with you, and they should be happy too, even if it's together. At the very least, if they get married now, at least I know they didn't betray me for the hell of it. At least I know it was the real thing for them."

"So you want to go to their wedding." She said, as she stepped out of the bathroom, already in make up and dress.

"I want to go to their wedding. I need to talk to Addison now, then maybe someday I will be able to stop hating Mark."

"You really want to make peace with them, don't you?"

"Yes. I do. I miss my family. Shall we?" he asked, giving her the smile that made her go week in the knees and offering her his arm.

"We shall." She smiled back, contentedly taking his offered arm.

She hadn't really understood then, that Derek was really serious. He considered Addison and Mark his family. And now, Mark was gone. And Addison was left alone. With a baby on the way. And Derek had spent the night at her place, just to make sure she was alright and to give her a ride to work on the morning. And for some reason, Derek seemed to be unable to understand why she was upset and she was feeling the urge to kick him.

"What?!" he asked, defensively.

"You can't do this to me now, Derek. It's not fair. This is about you and me and our life together. I'm sorry about Mark, I feel for Addison, but I'm not going to let you play surrogate husband and father for her."

"How can you say that?"

"Because that's who you are, Derek! The freaking knight in shining armor! And right now she's vulnerable and alone and you can't help yourself to want to fix her life and take care of her. But the truth is, you can't do this for her and you can't do this to me. After all we have suffered through, all the pain and ache and the wanting to be together, after every single thing we went through together, you can't leave me alone in this relationship. I love you Derek, and you love me, we go first. And you can't help out Addison, not really, unless you can bring Mark back so that she has a husband and her baby has a father." As soon as the words left her mouth, she could see the effect they had on him. His whole face and demeanor had changed, and his eyes were blazing.

"Are you done now?" he asked.

"No Derek, I'm not. If I were done here, with you, I wouldn't be upset that you spent the night at Addison's. I wouldn't care about you wanting to step into a situation that doesn't concern you…"

"It does concern me."

"What?"

"It does concern me. First, Addison is my ex-wife. She was my whole world for such a long time, and we don't hate each other anymore. So Meredith, I'm sorry, but you'll have to get used to the fact that Addison's a part of my life and that if she needs me, I'm going to be with her during this."

"Derek…"

"I'm not done. That's not it. There's also… Mark. I met Mark when I was four, he was my preschool best friend. Do you understand that? In all my life, there were only four years that didn't include Mark, and I can't remember most of those years, so I feel like I've known him all my life. And whatever else happened between us, Mark was my brother, my only brother. And I saw him grow up, and be a jerk and a jackass and finally, I saw him mature. He wanted to be there for Addison and he was looking forward to having a child. He was gonna make one hell of a father for their baby. But he won't get the chance. And Mark was my brother and he died. And Mark's wife, who happens to be another member of my family, happens to be pregnant. Addie will be pregnant without Mark, she'll have the baby without him, she'll raise him alone. And one day, that little boy will ask all these questions about who his daddy was, and I want to help Addison answer them. Because Mark was my brother and the very least I can do for him is make sure his son knows that he was wanted and loved by his father. So this is it."

"This is it?" asked Meredith, a little bit stunned by Derek's speech.

"Yes. I talked to Addison, and I asked her to let me be a part of this."

"What do you mean?"

"I mean everything. I can't replace Mark but I can give her what he would have wanted for her to have during her pregnancy. I want to make sure she eats right, that she's healthy, I want to do anything that she needs. And I need you to be okay with this. I love you Meredith, but I'm doing this. I'm not letting that little boy grow up without a father figure in his life."

"So that's that? You lay it out there and I'm supposed to just… accept it? Get over it? What, Derek?"

"I… I just…" he never got to finish that sentence, as Meredith left him standing in the hall by himself.