A/N: Hi everyone!

I've had so many more reviews on the prologue than I could have expected, so thank you so much for that!

I've had a lot of questions about what pairing this story is going to be regarding Alex, and I know there's no way to keep everyone happy, but here it goes: My aim is to pretty much follow the storyline of the show, with a few added plots in there for Katie. So yes, Alex will be with Izzie at some point, because I think their relationship was important to Alex's character development, but I didn't particularly like them as a couple (I don't think Izzie loved Alex as much as he loved her, and I can't even express how selfish I think she was to him when she left. Anyway, not the point...haha) so I won't be dwelling on their relationship in this story as much as in the show. I hope that's ok with everyone!

I have the next chapter written (and it is super long!) but I want to get the one after that written before I post anymore, so that I've always got one more written ahead (does that makes sense? :s haha)

Anyway, I'm going to shut up now lol! Please let me know what you think!

Thank you!

xoloveJBox

Chapter One

Nine years later

Alex Karev was content. He wasn't 'this-is-the-best-day-of-my-life-and-nothing-could-ever-ruin-it' happy, but it was almost seven thirty in the morning, and he was finally letting himself into his apartment building, heading for his bed after a thirty-two hour shift, where he'd managed to scrub into three surgeries, one of which he was unlikely to ever see again, so yeah, he was pretty pleased with himself. But he'd be lying if he said he wasn't tired, and although being a surgical intern meant he was used to long shifts, he was more than looking forward to a hot shower and his bed.

Alex glanced down at his watch as he dug around in his pockets for his keys. He knew that his sister would still be home for a few more minutes, and he smiled when he heard soft, light singing from inside his apartment, confirming his thought. He couldn't remember the last time Katie wasn't chatting or singing or humming, and if it were anyone else, it would annoy him beyond belief. In fact, she liked talking so much she learned how to do it in several languages, which was something that seemed to come so easily to her.

He let himself in and spotted his sister straight away. She had his back to him, but he could see the little white buds of her earphones in her ears. She hadn't noticed him, so Alex closed the door quietly and snuck up behind her, yanking an earphone out, making her scream.

"Jackass!" She yelled, flinging out her hand, punching him in the arm "You scared the crap out of me!"

"It's nice to see you too, Angel-face," Alex laughed heartily, amused at her reaction.

"I swear one of these days, I'm going to change the locks or something," She warned sternly as Alex continued to chortle while he shrugged out of his jacket and leant against the counter "I'd have the time to do it too, you know. Sometimes I consider giving myself food poisoning just to have the chance to have a conversation with you."

"Since when were you such a whiner?" Alex retorted, scrubbing a hand tiredly across his face.

"I have plenty of time to perfect my skills," Katie shot back with a smirk.

"Did you take your-" Alex started, but Katie was so used to the question that he didn't even need to finish it before she gave him an answer.

"Yep."

"How much sleep did you get?" He questioned, and Katie refrained from rolling her eyes.

"Eight and a half hours." She answered dutifully, deciding to just entertain his routine, just like she did every morning. Even if he wasn't going to be home, Alex called to interrogate her the same way each morning.

"You go for your run?"

"I did." Katie answered before grinning mischievously "God, how can you be this tired and still find the energy to ask me stupid questions?" She knew that even if she wasn't unflagging with her medication, her brother was diligent enough for the both of them.

Alex held his hands up in mock defence "I'm just making sure you don't forget."

"Have I ever forgotten before?" Katie challenged with an eyebrow raised at him.

"No." Alex admitted with a small, wry smile. He knew she was right-she'd been diagnosed with epilepsy when she was eight and although it had been a struggle to get her to take her meds at first, she'd never missed a dose, no matter how much she hated them.

"Well then." She concluded, going over to the fridge and pulling out a pizza box, tossing it onto the counter between them "Here, have breakfast."

"Left over pizza is not breakfast Kate." Alex chuckled lightly, though he opened the box and the two of them helped themselves all the same.

"I know, but we don't have anything else." Katie told him coolly, chomping casually on her slice of cold pizza "We need to go grocery shopping, because if I eat take-out for much longer, I'm going to get fat and pimply, and I do not need to add that to my list of things to make my life hard."

"Fine," Alex shrugged nonchalantly "we'll go when you get home from school if it means you'll stop being a drama queen."

"I'm glad to see that exhaustion isn't affecting your usual pleasant demeanour big brother." Katie commented cheerfully, not even bothering to hide the sarcasm that leaked into her tone, which only made her brother chuckle at her. Katie looked down at her watch and tried to hide her disappointment at the time it showed. "Shoot," she muttered "I have to go. But you should sleep, and I will see you after school."

Alex nodded, finishing his pizza now that fatigue was catching up with him in crashing waves, and Katie pecked a quick kiss to his cheek as she passed him, as she did whenever he was around when she was leaving for school.

"Oh, and I did the laundry last night, which means there are plenty of clean towels, so you should probably shower, because you kind of stink." Katie told him matter-of-factly as she gathered up her bag and jacket, shooting him a wide, playful grin over her shoulder "You're welcome!"

She had scurried out the door before Alex had a chance to reply, and he wondered, not for the first time in his life, how Katie managed to be such a cheerful kid. When he had been her age, Alex knew for sure that it was probably the most miserable time of his life. But, he didn't want to question it too much in fear that it would change if the universe thought he was being dubious, so he was happy to accept that Katie was just more stable than he had been-which was exactly what he had wanted.

With these pleasant thoughts running through his head, Alex sat under a quick, almost scolding shower before sliding under his quilt and falling into a blissfully oblivious sleep.

Alex cursed bitterly when his pager sounded on his bed side table, only four hours later. He wanted to ignore it so badly, and he briefly considered it, but when it beeped at him again, he huffed out an exasperated breath and threw back the covers, diving out of bed and jumping into the first clean clothes he could find.

From the moment he stepped back into the hospital, Alex was rushed off his feet. It seemed like everywhere he turned, someone else was demanding his attention, and he barely had time to breath for two straight hours. When things finally seemed to settle down a little, he decided that he'd hang around for another hour, and if nothing else happened, he'd head back home. In the mean time, he thought he'd head down to the tunnels, where he and his friends often hung out when they weren't busy, and try to get some sleep on one of the beds that were stored down there.

However, his hopes were short-lived, because when he got there, Meredith, George and Izzie were all down there, chatting casually while they ate lunch, and no matter how tired he was, Alex wasn't sure he'd be able to fall asleep while they were around.

"I thought you went home?" Meredith questioned curiously as he plonked himself next to them.

"I did." Alex told her shortly "I got called back in."

"Yeah well, you're a resident now," Izzie snapped "What did you expect?"

Alex ignored her, too tired to bothering arguing, and as much as O'Malley got on his nerves, Alex was grateful that he managed to steer the conversation away. He listened to them chatter for a while, joining in here and there, but he could feel himself dozing, so he wasn't too forthcoming with his contributions.

"Do you guys want to get drinks at Joe's tonight?" Meredith suggested cheerfully, and while there was a hum of agreement from Izzie and George, Alex stifled a yawn and shook his head.

"I've got plans tonight," he told them casually, making Izzie scowl at him. "What's wrong with you?" he demanded, expecting some snarky remark from the blonde woman who still seemed to resent him so much, and she opened her mouth to give him just that, but before she could get anything out, they were interrupted by a nurse emerging at the end of their tunnel hide-out.

"Dr Karev, there's a patient in the pit who's asking for you specifically."

"For what?" Alex questioned sharply, still annoyed at Izzie's incessant ability to hold a grudge, wondering why anyone would be asking for him.

"Sutures." The nurse replied simply, and Alex rolled his eyes impatiently.

"Get one of the interns to do it." He barked, scrubbing a hand tiredly over his face "No one's dying if they only need stitches. Get one of the interns; they could use the practise."

"Well then, her teacher needs to know who else she should call for Katherine." The nurse snapped curtly, annoyed at being ordered around so dismissively. "I don't have time to run around chasing you and your-"

"What did you say?" Alex asked, and Izzie was almost sure she saw the colour drain from his face.

"Who should I call for Katherine?" The nurse questioned impatiently, though she was caught off-guard when Alex jumped from his seat and pushed past her, taking off at a run down the corridor, leaving Izzie, Meredith and George wondering what the hell was going on.

A/N: Hi again haha

I just want to say that in my head, Katie is perky and cheerful, but at the same time, she can be sarcastic and down to earth, so the last thing I want is to portray her as annoying when she's being perky and cheerful, so if that's ever the case, please let me know!