He had known he'd be there. Old habits die hard. It had been almost two years since the last time they had jogged in Central Park at 7 PM on a Thursday night, which they had done religiously every week for seven years, barring unexpected emergency surgeries, usually on Derek's part.

"Mark."

"Derek."

They jogged side by side, speeding up a bit as if to test the other man's strength and stamina.

"I should've known you'd be in town, with the hotshot neuro congress and everything. You lecturing?"

"Yeah. Held it today, the rest of the week it's all drinking and playing golf. You know."

"So, how's life treating you and the little wife?"

"Well, life will take care of itself eventually, and the little wife and I signed the papers three weeks ago."

Mark knew immediately which papers Derek talked about. He stopped, and so did Derek.

"Seriously?"

"Seriously."

"So what happened?" Derek started running again, and Mark had to speed up to catch up with him. Mark started laughing, a bit out of breath. "Something tells me a certain lusty intern is involved."

"Stop calling Meredith a lusty intern."

"Well, how about I call her dirty mistress?"

"Do you want me to give you a scar on the other cheek for symmetry? You're about two seconds away from that now."

"I don't have a scar – see?" Mark turned his face to show Derek his other cheek, his face glistening with sweat, his wet t-shirt clinging to his back and chest. "Remember, I'm the best plastic surgeon on the east coast, Derek. I know how to stitch up a wound – I just work those magic fingers."

"Those magic fingers have gotten you in trouble before, as I recall."

Mark laughed. "Too right, my friend."

"Don't push it. We're not friends anymore, not after the stunt you pulled with Addison."

They jogged in silence for a few minutes, unconsciously falling back into each other's familiar rhythm.

"I slept with Meredith. I was madly jealous, messed up her relationship with a nice but oh-so-boring vet, then Addison found out, and the rest is history." He paused. "Well, it was history long before that, actually."

"How did she find out? Did she actually catch you doing the dirty deed?" Mark's voice was strained, and Derek realised why – he was feeling sorry for Addison because Derek had hurt her. He was still feeling protective of her.

"No, she didn't. She found Meredith's panties in my pocket."

Mark started laughing. "You know what, Derek? Everyone always thought we were a strange pair of best friends – that I was the wild party boy, and you were every mother-in-law's wet dream. But the thing is, deep down, we are the same, you and I. The only difference is that while I'm upfront about being an ass and sleeping around, you pretend to be all Mr Perfect, making yourself feel better about your cheating by being all guilty and looking puppy-eyed and wounded. You know what you are, Derek? You are an asshole."

Derek laughed. "I know. You're the only one, besides Meredith, who has ever called me on it. She said pretty much the same thing herself, although she didn't use the same colourful description."

"I take it you're not back together, then?"

"No, not really. Not yet, anyway. We're taking things slowly."

"Good for Meredith. She's too good for you, just like Addie was. I hope for your sake you don't mess up Meredith the way you messed up Addie."

"Why this sudden interest in Meredith's well-being?"

"We are both assholes – and we share the same taste in women."

"Just stay the hell away from her. I saw the way she looked at you."

"Derek, all women look at me that way," Mark laughed. Derek didn't answer.

They jogged in silence for a few more minutes, both breathing more heavily now. They were getting near the end of their old round.

"If you've got something to say, just say it," Mark finally said, angrily. They stopped, having reached the junction where Mark had used to jog home to his place, and Derek in the other direction towards the apartment that had been his and Addison's. Mark was angry, tired and sweaty, but Derek seemed to have something on his mind, something difficult, so he stayed.

"Addison and I talked about a lot of things recently. Not just about Meredith, but about you, as well." He paused. Mark didn't answer. "She told me that you had been sleeping together for two years before I found out."

"Derek, I'm... sorry. I wish there's something I could say, but..."

"But you loved her. I know. Did you know that she got pregnant?" From the look on Mark's face – complete and utter shock – it was obvious that he didn't. "It was almost three years ago. Back when you spent four months in Sydney teaching, remember? She found out, quite conveniently, come to think of it, just one week after you left. She had an abortion. It was her decision, I didn't really have anything to say about it. To be honest, I didn't really care that much. I mean, I cared, but... Not the way I knew I should've cared."

"The baby," Mark whispered. "Was it..."

"She didn't know who the father was. Could've been either one of us. Which was one of the main reasons why she didn't keep it, although she didn't tell me back then, of course."

"Poor Addie," Mark whispered. He looked absolutely devastated, quickly drying his eyes with the back of his hand, pretending to dry sweat off his forehead, but failing miserably. He feels the way I should've felt back then, Derek thought. But I didn't. And he knew why.

Right there and then, he made a decision, about something he hadn't been sure whether or not to say until now.

"There is a position open for a plastic surgeon at Seattle Grace. Naturally, the Chief wants no one but the best. He also knows very well who the best is, and just what happened between this certain surgeon and his two favourite attendings last year. Which is why he hasn't called you already."

"So?"

"So I'm asking you to call him."

"Why?"

"When you came to Seattle last year, you came to win her back, didn't you?"

There was no point in lying, Derek already knew the answer. "Yeah. But as usual, she chose the so-called good guy."

"You still love her?"

"Wish to God I didn't."

"She needs you, Mark. Although she'll never admit it, she's far too stubborn. She needs someone. And I think that someone's you. If you think you can work with me, I think I can work with you."

"Addie would kill you if she knew we had this conversation."

"I know. She'd kill you, too."

"She's far too intelligent not to realise something's happened if I suddenly show up at Seattle Grace."

"She was always smarter than either of us."

"Speak for yourself."

"You still want that second scar?"