Author's Note: This is my first story so tell me what you think. This just came to me so I wrote it down and decided to post it. It's about my favorite couple on Grey's Anatomy Calzona. This story is assuming that Callie and Arizona have been together for 1 yr already and they didn't get together until 6 months after Erica left. Enjoy! Sorry for any mistakes.

Disclaimer: I don't own any of the characters or places. I wrote this just for fun.

Chapter 1: Back at Seattle

Callie had just fallen asleep in one of the on-call rooms when someone came charging through the door. She woke up and quickly got up. She looked at Mark obviously annoyed.

"Mark I am trying to sleep here!"

"Are you okay?" He asked ignoring her scowl that she gave him.

"What do you mean am I okay?" She asked, "Why wouldn't I be?"

Mark looked at her sadly, "I'm guessing you haven't heard."

"Heard what, Mark what are you talking about?"

"I'm talking about your ex-girlfriend being here to do a heart transplant." He explained.

"Erica's here?" Callie asked looking at Mark as if she doesn't care.

"Yeah," he said giving her a strange look, "You look as if it's no big deal."

"It's not" she told him shrugging her shoulders.

"O-kay." He said splitting it into two words.

Callie looked at him and asked, "Can I go back to sleep now?" Then she lied back down and closed her eyes. She heard the door open and close.

Just as she was about to fall asleep Mark came barging in again. "How can you just be okay with this? Were talking about a woman who broke your heart."

"Mark I -" Callie tried to interrupt but he kept going.

"We're talking about a woman who left without saying goodbye."

"Mark." Callie tried again a little louder but with no luck.

By now Mark was yelling, "We're talking about a woman who you haven't seen or heard from for 1 ½ years and for all you would have known could have been dead!"

"MARK!" Callie yelled finally losing her patience.

"What?" Mark looked at her as if he just realized she was there.

"Calm down." She told him.

"Ok." He replied. A moment of silence went by when Mark finally broke it. "How can you be okay with this?"

Callie gave an exasperated sigh and looked at her best friend. "I've been trying to tell you but you wouldn't shut up."

"Okay I'm listening."

"I'm okay with this because I'm in love with Arizona."

"Huh?" Mark asked looking confused.

"Mark it's like you said, I haven't seen Erica in 1 ½ years. I don't have anymore feelings for her, plus it's like I just said, I'm in love with Arizona and I'm not going to ruin our relationship like I did with Erica. I can't live without Arizona. She's the one Mark. No one can change that, not even my ex."

"Wow, I guess you're right," Mark told her, "So when are you going to tell Arizona that Erica is back."

"It's not like she's staying Mark." Callie said rolling her eyes at Mark."

"But still," he told her, "I heard she's going to be her for a few weeks."

"It's noon right now so I'll tell her in a few hours."

"You don't have a few hours, maybe a few minutes, but not a few hours." Mark replied.

"What are you talking about?" She asked him laughing.

"Callie," he started off looking at her seriously, "The heart transplant she's doing is on a 10 year old girl who is already a patient of Arizona's which means they are going to be working together." Mark looked at her as the words sunk in.

All she said was, "Oh crap."

Mark's phone beeped signaling he had a text. "It's Lexie, she says Erica just arrived and got on the elevator."

"Oh crap" Callie said again, "help me find her Mark."

They burst through the door. Callie ran to check the cafeteria which is where she left Arizona before going to the on-call room. Mark goes to check the peds floor.

AN: Please review and tell me what you think. I already started writing the next chapter but I won't post until I get your feedback. If I get positive review then I'll post.