A/N Plot bunnies love me apparently.

Fear

Years from then Mark would reply that he had no memory of the ambulance ride to Seattle Grace and he would be telling the truth. He just remembered the paralyzing fear that he had. He needed Callie to be okay. He needed his children. God forbid if anything went wrong he'd blame himself forever. He never should have gone out for that damn ice cream. He should have been there with Callie. He had made a panicked call to Addison who had promised to meet them at the hospital. All he could focus on was Callie. He hadn't felt the normally extremely active babies kicking at all and that scared him more than anything.

Once they got to the hospital Addison stepped in and took over. Mark heard snatches of conversation, but he really wasn't paying much attention. He wasn't leaving Callie's side though Addison had enlisted Derek's help and Derek was trying to get Mark to step out of the room.

"Go Mark. I'll come get you as soon as we know something." Addison pleaded. Mark could see the look of fear in Addison's blue eyes and that caused a sinking feeling in his stomach. Derek grabbed his arm and steered him out of the room. He remembered the day Meredith had almost died and how terrified he had felt that day. And now he was with Addison again. It was bizarre how things could change in a matter of two years. Mark felt his legs buckle under him and he sank down to the cold floor beneath him

"She'll be okay, right? "Mark whispered.

"With Addie in there with her, she's got the best chance of being okay." Derek pointed out.

"We can make another baby. We can't make another Callie." Mark murmured, mostly to himself. He couldn't believe this was happening.

Addison knew what was going on but she hadn't wanted to tell Mark just yet. She needed a moment to collect herself. Callie's uterus had ruptured and the sudden blood loss had probably caused the fall and the injury to her head. There wasn't much else to do except to deliver the babies. At 28 weeks, they had a long road in front of them, but Addison had delivered younger babies than that and they had survived. She came out of the room wearing a very solemn look on her face. All the color drained from Mark's face. He could only guess what that meant and he hated that feeling. He may not have believed in a God but ever since he had found Callie he had been praying.

"Addie?" Mark asked as he stood up slowly and shakily fully expecting his legs to collapse under him.

"A uterine rupture caused all the bleeding and caused her to fall and hit her head." Addison told him quietly. Mark had to bite the inside of his cheek to stop the tears from falling. His Callie and his children were in trouble.

"Will you have to do an emergency Cesarean Addie?" Derek asked, knowing that Mark could barely formulate words, let alone questions.

"Yes and we need Mark's permission." Addison told Derek but looking at Mark. Mark felt the urge to vomit. This was not how it was supposed to happen and he was angry that it had happened like this.\

"If it comes down to the babies or Callie, you save Callie Addie. We can always make more babies but we can't make another Callie." Mark finally told Addison. He was trying to keep the tremor out of his voice but he was failing miserably. Addison could tell that Mark was falling apart and Addison didn't think she could watch that. He was too good of a friend to her and they had been though so much together. Addison was so glad that levelheaded Derek was with him.

"Okay." Addison agreed with a nod. She didn't think Callie would agree with Mark's choice but Mark was the one who got to make these decisions.

"And I'm sitting in the observatory." Mark added. He was firm on that. He knew he wouldn't be able to be in the actual OR, but he figured this would be an okay compromise. Addison knew that arguing with Mark would be pointless so she just nodded.

"Okay." Addison agreed. Mark was relieved that she wasn't going to fight with him on this. Addison went back into the room to prep Callie for the emergency Cesarean.

A short time later Mark and Derek were in the observatory. Mark was glad that Derek had insisted on being with him. Mark knew that if the worst happened he would need his friends. Watching Addison work quickly, Mark couldn't help but think of the names that he and Callie had already discussed and wondering if any of them were right.

"This wasn't supposed to happen so early." Mark commented softly. Derek sighed, recognizing that voice in his best friend. He knew that his best friend was hurting and he didn't want to see that. He knew that his best friend was terrified.

"Should we call her family?" Derek asked. Mark shook his head. He needed to know they would be okay first before he involved family.

"After the surgery when we have more to tell them." Mark told Derek. Derek nodded as they slipped back into silence and watched Addison make the first cut.

Down in the OR, Addison was scared and she didn't like that feeling. She wanted to feel confident and sure of herself. She didn't feel either of those things. Cutting open her best friend was something she did not want to do but it was something she had to do. Within a minute she had delivered the first baby and it was a boy and a girl quickly followed the first. Mark and Callie had one of each. Addison wished that Callie or Mark had shared name ideas with her because she hated calling them Baby A and Baby B. It was so impersonal.

Up in the observatory Mark couldn't believe he had one of each. He had a son and a daughter. He just had to hope that Callie would be okay. He was smiling through a mist of tears. He knew Derek wouldn't comment on the tears and he was grateful.

"I'm a father." Mark murmured. He still was finding it so hard to believe.

"Yeah you are. Congratulations." Derek told his best friend. He wasn't at all surprised that Mark had kids before him. What he was surprised at was the fact that Mark's kids had come with a stable relationship and possible marriage soon. Mark didn't wait another minute. He got up and ran out of the room, planning to meet the babies in the NICU. He knew that Callie would want him to stay with the babies and that was his plan. Wordlessly Derek agreed to go check on Callie. Mark beat the NICU team and once they arrived, Mark stepped outside so they could settle the babies in and stabilize them. Derek and Addison came up behind him. Addison put her hand on Mark's shoulder and Mark turned around to look at Addison.

"Your son was 2 pounds exactly and your daughter is 1 pound 6 ounces." Addison told him softly. Mark smiled a soft smile. His kids were tiny, but they were fighters.

"Callie?" Mark asked, his voice raw with unshed tears. She had to be okay. He couldn't lose the mother of his kids and the woman he loved. He was afraid to hear the answer because he hadn't stayed to watch them close Callie up.

"She's going to be okay. She's having another blood transfusion, but things went well." Addison told him. Mark let out a breath that he didn't even realize he was holding.

"I should go to her." Mark told Addison. Addison shook her head. Mark was right where Callie would want him to be. Addison knew that Callie would want Mark to stay with the babies.

"Callie would want you to be right here." Addison insisted. Derek nodded, knowing that Addison was right.

"Yeah, you're right." Mark agreed. Addison smiled at Mark. She could tell that he was genuinely torn.

"I'll stay with Callie. You stay with the babies." Addison told him seriously. Mark was glad that Callie wouldn't be alone.

The team finally thinned out and Addison gave Mark a light little shove in the direction of the two incubators. Mark went straight to the incubators that held his children. Derek and Addison slipped away and left Mark alone with his kids. Mark couldn't take his eyes off of his children. He could hardly believe that he was a father. He needed to do this right. He needed to make Callie his wife. He swore to himself that he would do that when Callie and the babies were home with him.

Addison settled down beside Callie's bed, knowing that Derek had gone to get food that he would be shoving down the new father's throat.

"You and Mark make beautiful babies sweetie." Addison told Callie. She wished Callie would wake up. She figured she could just keep talking about the babies and maybe that would wake Callie up.

"You have a son and a daughter. And a boyfriend who is going to be an amazing father to them." Addison murmured. Callie had been taken off the ventilator already which was a good sign but she wasn't waking up. Finally Addison felt Callie's figures move.

"Come on sweetie. Your children and Mark need you." Addison pleaded as tears slipped down her own cheeks. This was really hard on her and finally she was reaching her breaking point.

"Mark?" Callie's raspy voice finally asked. Addison looked at her and smiled. She wasn't surprised that Mark was the person Callie wanted to see first.

"He's with your kids. I'll go get him." Addison told Callie. Callie couldn't believe that she had actually given birth to her twins already. Not in the way she had intended to either. She hated knowing that she had delivered the babies at twenty-eight weeks. Twelve weeks early.

"Thanks." Callie whispered. Her eyes drifted back closed as Addison left the room to go get Mark.