Author's Note: This is an AU Grey's Anatomy Fanfiction. There's no Jo. There's no Stephanie. The original cast is still alive and well, just in different situations. Addison never went to Seattle for the consult and got back together with Derek. Those who died never died. The only character I own is my O/C; the rest, unfortunately, belong to Shonda Rhimes.

PROLOGUE

"Derek, you can't do this," Addison plead, as she followed her husband to the front door of the home they shared together in New York. "Derek, please, we have to talk about this! You have to give me a chance to explain! What are you doing with my clothes, Derek?!" She ran after him, wearing nothing but a t-shirt. Her words started coming out so fast, even she didn't know what she was saying at that point. Her heart was beating out of her chest, her body radiating with adrenaline and guilt. Derek descended the stairs, and Addison chased after him, trying her hardest to get him to listen to her. "He was just here, he was just here, and—"

"You screwed my best friend, and all you can say is 'he was just here?!'" Derek interrupted, pulling open the front door. A gust of wind flew in through the door. Rain was falling, the sound of thunder nearly drowning out his words. He threw her clothes down out the front door. He didn't have a care in the world about those clothes. He wishes it was her he had thrown out the door. "Get out," His voice was so monotonous, it almost scared Addison.

"No," She rebutted, gripping onto the handrail of their staircase.

"Get out!" He repeated, raising his voice a little louder. "Get out of my house!"

"No," She refused again. "Derek, I'm not going anywhere! I'm holding my ground."

"Get out!" Derek shouted, as Addison sat at the bottom of the staircase, gripping the rail even tighter.

"No! I'm holding my ground, Derek! We don't quit! What are you doing?!" Addison shouted, as Derek grabbed her by the arm, dragging her toward the door. He pushed her outside, slamming the door in her face. The sobs Addison had been holding back escaped with a vengeance. Catching her breath was not an option.

"Please," She begged. "Please, Derek!"

Derek opened the door, a blank expression on her face. "I'm sorry," she sobbed. "I'm sorry, please, you have to give me a chance to show you how sorry I am, please!" She wrapped her arms around him. She placed a hand on his back, but she knew it was half-hearted. They had been married for twelve years; she knew what this meant, but she was in denial. She put her hands on either side of his face, leaning in to try to kiss him. He pulled away from her and closed the door.

"You stay," He spoke. "I'll go. I'll get my clothes in the morning."

That wasn't the reaction she was expecting. Panic arose in her chest again. "No, no no no, Derek, no. We can survive this. We're… we're Addison and Derek…"

"I can't look at you," He turned his head. "I look at you, and I feel nauseous. I just…" Tears finally fell from Derek's eyes. "We're not Addison and Derek anymore."

"Derek… Derek, please… if you go now we won't get through this! If you go now, we don't have a chance!" Derek turned his back on Addison, ignoring her pleas and walked out the front door.

Addison collapsed on the floor, broken sobs escaping her body. She put a hand on her chest, trying to force herself to breathe. She couldn't breathe. "Derek…" She cried. It felt like she'd never stop.

She forced herself off of the floor. She crawled to the downstairs bathroom, where she was when she heard Mark knock on the door. She had been so thrilled just hours earlier… now it felt like everything was crumbling around her. She pulled herself up on the sink, her legs shaking so violently it felt like she might collapse again. The little blue stick with two lines seemed more like a catastrophe than something to be excited about.

Addison knew she couldn't tell Derek. She knew, deep down, she had screwed up, and screwed up bad. He had every right to leave her, even though she really didn't want him to. She didn't want him using this against her to take her baby. Her hand went to her stomach, and she took a deep, shaky breath, trying to calm herself. She knew stress was bad for the baby. Her baby.