Disclaimer: I don't own ER or any of these characters, etc.

Summary: I'm a huge Mark and Susan fan, and this is just my imagination running wild as to what might have happened between them. I'm already working on more chapters so please read and review and tell me what you think. Enjoy!

Chapter One – The Reunion

Set after the end of Series 6

When Mark and Elizabeth had left Chicago, it had been raining; by the time they had reached Seattle, the sky was clear and sun was shining brightly in the sky. They were visiting Carol and Doug, whose twin daughters, Kate and Tess, were being christened. Mark and Elizabeth had been asked to be godparents.

They arrived at a quarter to five, and were greeted by Doug.

"Hi," said Doug, with a huge grin on his face. "Long time no see." Doug kissed Elizabeth on the cheek before embracing Mark in a bear hug.

"How was your journey?" Doug asked, as he helped them to unload their bags.

"Good," replied Elizabeth. "How are you?"

"Pretty damn good," Doug replied, with a smile which spread across his face from ear to ear. He certainly looked happy. Life in Seattle obviously suited him, although Mark personally believed that it was life with Carol that suited him best. They chatted as Mark and Elizabeth followed Doug into the house. They walked through the hallway into the lounge, which was adjoined to the kitchen, where they found Carol.

"Hi!" she said when she saw Mark and Elizabeth. She gave them both a hug. "Its so good to see you guys."

"You too," said Mark. "Where are those gorgeous girls of yours?"

"Outside with my mom," replied Carol. Mark raised his eyebrows at Doug, who laughed. It was well known that Doug had never really got on with Carol's mother.

Carol and Elizabeth stood chatting, while Doug and Mark moved into the kitchen to get drinks.

"You and Carol going well?" Mark asked.

"Terrific," Doug replied. "I've never been this happy. How are things with you? I was sorry to hear about your parents."

"Thanks," Mark replied.

"And what about work? I hear things have been tough at the hospital recently," Doug asked, referring to the incident in which Carter was stabbed and Lucy was killed.

Mark nodded. "It's not a happy place to be at the moment. But it has its good points," he said, looking across at Elizabeth.

"So, how are things between you and Elizabeth?" Doug asked.

Mark smiled. "She's a great woman. So, tell me about your job?"

Mark didn't hear the reply as he became distracted by a familiar sound outside. A laugh. He turned to look out of the window, which faced the garden. He saw the back of a small, blonde woman, with a young girl aged about five. Susan Lewis.

Doug, whose voice had trailed off unnoticed, followed Mark's gaze.

"Did you know she was coming?" he asked. Mark shook his head.

"It's been a while since we've spoken." In fact, it had been over a year. They had spoken sporadically since Susan had left three years earlier, but the phone calls had become few and far between. Mark left Doug in the kitchen and walked towards the party of people down by the water. Carol's family were fussing around the twins, while Susan was playing with the little girl, who was screaming and laughing.

As Mark approached, Susan looked up and smiled. "Hey, stranger," she said.

"Hi."

They hugged, awkwardly, not sure of what the other was thinking.

"It's good to see you," Susan said.

"You too. You look great," Mark replied. "How's life in Phoenix?"

"Good. How are you?"

"Good."

An awkward silence followed, which was interrupted by the young girl.

"Aunt Susie, Aunt Susie, are you playing?" she said as she ran up and took Susan's hand. Susan smiled at her.

"Susie, I want you to meet someone. This is Mark," she said. She turned to Mark. "This is little Susie, only not so little anymore!"

Mark knelt down and held out his hand. "Hi," he said. Little Susie looked up at Big Susie, who smiled reassuringly, before taking Mark's hand and shaking it violently.

"Hello," she said. "Do you want to play too?"

Mark laughed. "I just got here, maybe later?"

"Ok," little Susie replied, skipping off still holding on to Susan's hand.

"I'll see you later," she said, as she was dragged off.

Mark returned back to the house.

"Who was that?" Elizabeth asked.

"Susan Lewis, an old, uh, friend. She used to work at County," Mark replied, slightly distracted by the uncomfortable atmosphere that had surrounded the meeting and not really sure of how he was feeling. Elizabeth did not notice, and she wrapped her arms round his waist. Mark put his arm over her shoulders in response and kissed her forehead, unaware of the pair of eyes that had followed him from the garden.

A short while later, Carol caught up with Susan in the garden.

"So, how did it go?" she asked, referring to Susan's encounter with Mark.

Susan rolled her eyes in response. "Oh my god, it was awful. I didn't know what to say. We made small talk before Susie pulled me away. He's still mad at me, isn't he? I know it, he's mad at me. Maybe this was a bad idea, all of us staying here."

Carol laughed. It amazed her that someone as level-headed as Susan could act so neurotic at times.

"I don't think he's mad at you," she said.

"So, what do I do?" Susan asked.

"Talk to him," Carol replied.

"But what if I bring up all these old memories and he gets mad?"

Carol laughed again. "There's only one way to find out."

Susan caught up with Mark later that evening in the kitchen getting drinks, whilst everyone was enjoying a barbeque outside.

"Hi," she said, nervously.

"Hi," Mark replied, glancing up and smiling.

"Can I give you a hand?" she asked.

"No, I got it. Thanks."

The awkward silence was back again.

"Little Susie seems like a handful," Mark said.

"She has her moments," Susan replied. "Elizabeth seems nice."

"She is."

More silence.

Susan took a deep breath. "Are you mad at me?" she asked.

Mark looked up, slightly taken aback by the directness of the question. He didn't respond.

"I mean, things are weird between us, and I understand that, but I don't want them to be, and if you're mad at me, I want to try and make it right, not that I know how, but…"

"Are you going to come up for breath any time soon?" Mark interrupted, laughing. Susan opened her mouth to respond, but didn't know what to say so she closed it again.

"Look, I'm sorry things have been weird since I got here. I don't want them to be either," Mark said.

"Are you mad at me?" Susan asked again.

"I was," Mark replied honestly. "For a long time I was. I was mad at you for leaving and not giving us a chance. I was mad at you for not being there when I needed you. But it wasn't just you. I was mad at me for not telling you how I felt sooner. I thought I could've stopped you from leaving if I'd done things differently. But, you know, life's been pretty crappy recently. Jen and Rachel moved to St Louis, so I hardly ever see my daughter. My parents died. We had a maniac come into the hospital with a knife, killing a med student and stabbing…another doctor…and you know what? I missed you. I missed my best friend. There were so many times I wanted to pick up the phone…"

"Then why didn't you?" Susan asked. "I would have listened. I missed you too. I waited so long for you to call, and you didn't, and I guess I was too scared to call you because I thought you'd just hang up on me."

"We made a bit of a mess at staying friends, didn't we?" Mark said, smiling.

"Yeah, we did."

Mark sighed. "Look, can we just put it all behind us and try again. At being friends?" he asked.

"I'd like that," Susan said. "So, can I give you a hand?"

Mark smiled and held out some glasses filled with wine. "Sure."