A/N: This was supposed to be a one-shot, but it turned out to be too long, so I'm doing a two-shot. Hopefully I'll post the second part tomorrow.

Now, the idea for this fic came from Paramore's song "The Only Exception". It's very loosely based on it.

I hope you like it.

The Only Exception

When Katie Beckett was in sixth grade, she had her first crush on a boy. His name was Tyler Phillips and she thought he was the cutest boy in her class. She tried to make him notice her and, months later, a kiss happened during her best friend's birthday party. She had gone to the kitchen to grab a soda and he followed her there. They made small talk (she was so nervous that her palms were damp with cold sweat!) and the next thing she knew, he was pressing his lips awkwardly against hers.

She went home that night feeling like the luckiest girl in the world (she had been the first out of her friends to get kissed on the lips by a boy. Was that awesome or what?) and happily recounted her tales to her mom. The next day at school, Tyler behaved like nothing had happened and a few days later, when she confronted him, he told her he had just wanted a kiss, not marry her. She told him he was a jerk and turned her back on him, walking away with her head held high.

Later, at the comfort of her bedroom and in her mother's arms, she cried, mourning her first lost love.

After that she was bit weary of boys for a few years. She had gone on dates in high school, but nothing ever came out of them, not even during her rebellious phase. She got the physical aspect of being with someone, but she never found what she was really looking for. Even though she showed the world that she could have a no strings attached relationship, inside she was screaming for romance. She wanted to find her Prince Charming and have that kind of love that took her breath away and made her feel like flying.

When she left for college, she had come to terms that maybe this romance thing just wasn't in the cards for her. Then she met Ben Carmichael. He was a biochem major and they met at a party. It felt like love at first sight. She was so excited to have finally found someone she could see herself sharing a life with. Maybe she wasn't cursed like she had previously thought. Maybe there was hope for her to have her happily ever after.

They were together for four months. In January 1999, her mom was murdered. That same year, in February, she caught Ben in bed with her roommate.

She kicked them both out of her life and they took away her hope to love and be loved with them. Her mother's death took her strength away. Ben had been the only good thing holding her together at the time and after he left, she felt like she was drowning. She didn't even miss him; hadn't even been in love with him yet (although she had certainly thought there was potential for that), but she felt like he had been her life preserver in a stormy ocean. With him gone and her father's dive into alcoholism, she couldn't keep her head above the water. She felt like she would suffocate at any moment.

One day, almost a year after her mom died, she was waiting for her dad so they could go to an AA meeting. She felt tired all the time; there were dark circles under her eyes and she felt like she was carrying the entire world on her frail shoulders. All she wanted was to find someone that could help her hold herself together. It couldn't be too much to ask, right?

She walked into a book store and a book caught her attention. It was a mystery novel by this new author called Richard Castle. She had read something about him in the paper the other day; he wasn't even 30 years old and was already on his fourth bestseller. Intrigued, she started reading the first few pages. Twenty minutes later, she was startled out of his fictional world by her dad. She had been so lost in Richard Castle's words that she hadn't even heard her father calling her name for the past two minutes.

Katie Beckett didn't think twice before walking to checkout, book clutched in her hands against her chest, and paying for it.

That book saved her from the world of darkness she had been living in since that cold January night.

After that, Richard Castle's stories became a constant in her life. His books were the one place she could always return to when things got tough or when she needed to get away from her reality for a couple of hours. Richard Castle became her most reliable source of comfort.

She dated here and there, but none of those men caused her heart to beat faster or the butterflies in her stomach to try and stage a prison break. She tried hard to feel something for them, but it just wasn't there. It never was.

And she suddenly found herself okay with that fact. Her life didn't need to revolve around romance. She had just been promoted to detective status and she couldn't be happier. She figured that if she was meant to find someone, it would happen sooner or later.

Then she worked with Will Sorenson in a case and she thought she saw the potential for a spark there. She was excited. Maybe she wouldn't be doomed to live a loveless life, after all. They dated for six months and then Will accepted a job offer in Boston.

He left her behind.

She came to the conclusion that maybe this was how her life was supposed to be and that she shouldn't dwell on it so much.

When she caught the case that copied the MO Richard Castle had used in his books, part of her was insanely excited to meet her idol. She had been to autograph sessions, but those things were always so rushed that she had never worked out the courage to say more than her name and thank you when he handed her the book back. But now she would have to talk to him, interrogate him.

It thrilled and terrified her at the same time.

Then Richard Castle proved to be a pain in the ass. The image of the brilliant author she had had until then crumbled to the ground and an immature playboy took its place. When he first started shadowing her, she couldn't stand him.

But somehow, along the way, she found herself enjoying his company. When he wasn't being a complete childish jerk, he could be funny and nice. Of course he hit on her all the time and invaded her personal space at every chance he got, but she didn't let it affect her. Or rather, she didn't let him see that it affected her and gave back as good as she got.

Will Sorenson came back to New York and she thought that the universe was giving them a second chance. Maybe, just maybe things could work out this time. But he got shot. Castle told her that he had been investigating her mother's case and had found something new.

Detective Kate Beckett felt overwhelmed. It was too much at once. Will left again (and she wasn't surprised this time) and she banished Castle from her life. She had asked him to respect one thing and one thing only. If he couldn't do at least that, then she couldn't trust him with anything.

Suddenly she found herself alone again. No love, no comfort from Castle's books. This time, she had lost an old boyfriend, her safe haven and something very close to a friend.

Oh well.

Up until then, she had sworn to herself that she was content with loneliness. No one that crossed her path seemed to be worth the risk.

Somehow, Castle wormed his way back into her life. Although she acted annoyed around him, she was more than pleased that he came back. She would have denied it even under torture, but she had actually missed him. Not that she would ever tell him, of course.

The months passed by and her feelings for Castle started evolving. When she looked at him, she saw him as a friend and as the potential for something more. She knew he reciprocated her feelings, but she was still afraid. His reputation spoke for itself and she wasn't too keen on putting her heart on the line just to be left in the dust when he got bored of her.

So she tried to ignore her growing feelings for her favorite author (she was beyond flattered that he was basing the protagonist of his next book on her, but she would never tell him that) and carried on with her life. When Detective Tom Demming asked her out and she said yes, it had felt like the right thing to do. But then Castle looked so miserable that she didn't know what to do.

Tom was a gentleman and treated her right. She had fun with him and he seemed to genuinely care about her. She couldn't say she was in love, but… you know, he was a good place holder for whoever it was that it was supposed to be in her life. She didn't believe that she would ever find her Prince Charming, but that didn't mean she couldn't distract herself in the meantime.

As the weeks wore on, her relationship with Castle got more and more strained. He looked devastated. She knew he was trying to hide it and play it cool, but at this point, she already knew him. The fact that she was dating Tom was bothering Castle and she had no idea why. If he was jealous, why didn't he just say so? It wasn't like he could ever just keep his mouth shut.

But he never did.

It took Esposito spelling it out to her for Kate to finally take action. She wanted Castle (she wouldn't be hypocritical and deny that her feelings for him had ever disappeared) and he wanted her, so why not do something about it, right?

She broke up with Tom and took a deep breath to gather the courage to go talk to Castle. She wasn't used to wear her heart on her sleeve like that, but she couldn't deny this anymore. It was a big risk and she knew that it could potentially ruin everything between them. But he wanted her too. They would be okay. They should at least try.

Then his ex-wife appeared out of thin air and whisked him away for the summer in the Hamptons.

Kate Beckett was once again left alone and promised herself she would not go through this again. This heartache just wasn't worth it.

It wasn't like it was love.

During that summer she met Josh Davison. He was a cardiothoracic surgeon and such a nice guy. They hit it off immediately and even though that spark she longed to feel was missing, he was a good distraction from Castle. It had been over two months already and he hadn't even called.

Kate resigned herself, thinking it was probably for the best. She and Castle wouldn't have worked out, anyway.

Then he came back. Once again, he wormed his way into her life and this time he started breaking down her walls more easily. He became her safe haven. Not his books, but him, Richard Alexander Rodgers, the man behind the famous author. They saw each other every day, even during the weekends. When she had a day off and Josh and Gina weren't available, they would always do something together.

She relied on him more and more. When Detective Raglan called her that day, she didn't even think twice before going to his place and asking him to be there for her. He understood her in a way that no one ever had. Those three days were hell for her and Rick Castle was her rock. He was the life preserver that she held onto so she wouldn't drown in her obsession again. He helped her hold herself together.

He kissed her.

He saved her life.

She felt that spark.

A few months later, she realized that what she felt for Castle could be described as love. She didn't know when it happened. She just suddenly had this epiphany one day when she was watching him cook at his loft. She had broken up with Josh three months before and they were both single and seeing each other outside of the precinct more and more.

He was making some mac and cheese for them after a long day at work. They had been working since 5am and she was exhausted. He had offered to cook them something and then a movie night for her to relax and she couldn't say no. Once they were at the loft, she wanted to help, but he just told her to enjoy her drink and let the master work his magic. She rolled her eyes at him with a small smile and he grinned at her with a wink, turning back to the stove to work on their dinner.

That was when realization dawned upon her.

She loved him.

And she was okay with that.