AN: Okay. First off, this is set five years after the season five finale. Second, this fic deals with the development of a mental illness. Throughout the fic, there will be mention of alcohol abuse, promiscuity, and self-mutilation. If that bothers you then please don't read it. The rating is M for these reasons. Thanks and I hope you enjoy!

Special Thanks to Brinchen86 and afrozenheart412 for helping me out a little. Super special thanks to Brinchen86 for reading this beforehand and reaffirming my faith in the story.

Disclaimer: I own nothing except Kristina and the story idea.

Kristina Young walked through the bullpen of the 12th precinct. It was her second favorite place next to the crime lab upstairs. This was the same precinct that her entire family had worked in for years. And now she was there.

Kristina had been working in the lab for a couple of years now. Although her father had wanted her to strictly be a detective and eventually a captain, Kristina loved the lab. Chemistry and math had always been her best subjects in school. So when Mac Taylor had offered her a position as one of his detectives in the lab she couldn't turn him down.

Of course, Don Flack had made fun of her. He had told her that she would turn into a nerd if she worked there. Kristina had kindly reminded him that some of his closest friends worked in that same lab. To which he replied that he was very aware of that fact and that they were all indeed nerds.

'I'm only looking out for your well-being' Flack had told her. That statement had earned him a playful punch on the arm.

Kristina loved Don Flack to death. Their fathers had been partners way back in the day, so the two had more or less grown up together. Even though Don was a good ten years older than Kristina, he had always included her when he hung out with her brothers.

This was something that never changed even as they had gotten older. If he wanted to go out for a couple of beers or to shoot some pool, Flack always called Kristina. Thanks to this, she had already known most of her colleagues at the lab before she even thought of working there.

It was Don Flack that she was on her way to see. Kristina smiled as she approached his desk and saw him hunched over it. He was writing something in his left handed chicken scratch that only she seemed to be able to decipher. She walked up to him and cleared her throat causing him to look up.

"Kris!" Flack said with a smile. "To what do I owe the pleasure?"

"You, dear Donald, are taking me to lunch."

"Was this something we planned and I just forgot about it?" he asked looking a little concerned. Flack never forgot plans with Kris.

"Nope, I was just hungry and I realized that we haven't had lunch in forever so I decided to let you buy me food."

"Awe, how generous of you," he said sarcastically.

"I know. I'm an extremely generous person," Kristina said with a smirk.

"Okay wiseass. If you want me to buy you food, then we better get going. I've got a ton of paperwork to do today."

At that moment Kristina's cell phone went off. She glanced at it and groaned. "Looks like I'll have to take a rain check. Someone just fished a dead body out of the Hudson."

Right after Kristina said this, Flack's phone rang. He looked at it and smiled. "I just caught the same case. Why don't you run upstairs, grab your kit, and meet me at my car. We can grab a slice on the way."

"That sounds great! I'll be just a few minutes." Kristina gave Flack a small hug and left to head back upstairs.

Flack watched her leave and smiled. He really loved that girl with all his heart.

"Ya know as good as this pizza is, you still owe me a decent meal," Kristina said to Flack as she took a huge bite.

He laughed and said, "Okay, how bout I come over to your place tonight and cook dinner?"

"Hmm… that sounds like a plan. But why don't I just come over to your place? That way you don't have to carry everything to mine." Kristina noticed Flack tense up as she said this. She knew exactly why he had done it. "Don, it's been five years. You still haven't let another woman in your apartment?"

"No." Flack sighed. He turned in his seat and looked her in the eyes. "I just can't do it Kris. I'm not ready to move on. I don't want to move on. I really cared about her. I think I was starting to fall in love with her. And then it was all taken away from me."

Kristina sat there silently and listened to him. She knew exactly what he was talking about. Exactly how he felt. She was the last person that would push him to move on.

"I hope you know that I'll always be here for you Don; just like you were there for me."

"I know Kris. Thanks. Love you."

"Love you too."

Flack wiped away the tears that had started to form in his eyes and started the car. "We better get going. Otherwise people will get the wrong impression of our relationship."

Kristina laughed at the idea. Their relationship. They had an extremely complicated relationship with an equally as complicated past. She wondered if that would ever change.

Several Hours Later

"No! I swear to you it was Sam's idea to put it under your pillow! I was just the stupid, young child who did what she said," Kris pleaded.

"But you actually put it there!" Flack exclaimed.

"Okay maybe that's true, but how was I supposed to know it would affect you that bad? To be honest that's what we were trying to find out. We wanted to know just how allergic to cats you are. And apparently a single hair under your pillow is enough to keep you up sneezing all night," Kris teased.

"You're a bitch. You both are," Flack said lightly. Although she knew he was teasing, Kristina faked a hurt look. "Oh don't even! I know you're a robot and nothing gets to you."

Kristina just laughed at that comment. In all honesty, he was half right. At least that's how she used to be. She noticed that is expression suddenly got serious.

"Kris…" He started to say something, but his voice trailed off. He sat there and silently worked his courage up again. "H-how long after Nate died did you start dating again?"

Kristina was taken aback. This was the last thing she had expected him to talk about. It was still a difficult subject for her. She could imagine how hard it was for him too.

"Honestly? I still haven't started dating again. I mean, I've had a couple of flings here and there, but no real dating. Of course, you already knew that. Why do you ask?"

"I don't know. I mean what you said earlier about it having been five years and I still haven't let another woman in my apartment. It got me thinking."

"You don't have to explain. If you did, you'd be preaching to the choir. Christ, Nate died almost ten years ago! And I'm still not dating anyone. I'm worse off than you are."

Flack smiled. "We really are pathetic aren't we? At least we understand each other."

"Like two peas in a pod. But yeah, we are pretty sad," Kristina said with a laugh. Flack threw a piece of broccoli at her and it landed on the floor. "You are so picking that up mister."

"Oh yeah? Make me," Flack replied crossing his arms.

"Seriously? You're going to sit there and act like a fuckin five year old? Fine then. You don't get any of my alcohol." Kristina smiled. She knew she had won with that statement.

"Oh that's okay," Flack said. He got up and went into the kitchen and returned with a bottle of tequila. "I brought my own."

The look of shock that appeared on Kristina's face was enough to make Flack laugh. He walked over and picked up the piece of broccoli. As he stood back up, he paused at her ear and whispered in it.

"Don't worry. I'll be a nice five year old and share."

Kristina walked into the locker room and slowly sank onto the bench in front of her locker. Her head was pounding and she knew that if she even caught a whiff of food, she'd be hunched over a toilet. She knew that Flack was probably feeling the exact same thing at that moment.

They really should not have had that bottle of tequila. Or the bottle of vodka. The bottle of wine with dinner would have been enough, but no. They just had to keep going. She laughed as she remembered the drunken conversation they'd had the night before, right as they were going to bed.

"I'll just be going home now then," Flack slurred.

Kristina looked at him and laughed. "Donald Flack, there is absolutely no way you can drive right now. You can barely stand up. You are staying here tonight. You can get up early and go change for work," she insisted.

"Well if you insist," he replied as he made his way to her bedroom. She grabbed his arm to stop him.

"What in the hell do you think you're doing? You are not sleeping in there!"

"But Kris, I need a good night's sleep. I have to work tomorrow."

"You can sleep on the couch Don, or you can leave. You and I both know exactly what'll happen if you sleep in my bed."

"What like it hasn't happened before?" he snapped at her.

"Oooh Don, don't you dare start that shit with me. We can not get into this now."

"Well when are we going to get into it Kristina?" He didn't call her by her nickname. He only did that if he was angry. "We've never talked about what this is between us."

"Look Don, I promise we'll talk about it. Soon. But not now. We both have to work tomorrow and we're both really drunk. We just need to sleep and we can discuss this tomorrow night."

"Promise?"

"I promise."

"Okay, I'll sleep on the couch. Good night Kris."

"Night Don."

Of course, Flack didn't stay on the couch all night. Around three in the morning he had crawled beside her in bed complaining that the couch was too uncomfortable. She was too tired to argue and fell asleep in his arms.

Kristina knew that they would have to talk tonight. Talk about whatever was going on with them. She didn't want to though. In fact, the last thing she wanted to do was talk to Don Flack about their relationship. Or lack thereof.