A/N : Beta by Diana :)

Disclaimer: Not Mine.

Pain.

She felt pain.

But the pain was wrong. It was different from the pain caused by a gunshot wound.

Kate opened her eyes.

She was in her motel room and it was still dark out. Castle and Jerry Tyson were nowhere to be found.

It was a dream.

It had all just been a dream. She had literally flung her body out of bed, ending up on the floor in a tangle of limbs and blanket.

Tyson didn't have Castle. He was safe. He had to be.

Kate fumbled for her cell phone, scrolling through her contacts for Castle's. Her thumb hovered over the screen, poised to tap "call".

She wanted to call him so badly. She needed to hear his voice, to confirm that he was indeed safe and alive.

But she couldn't. It was, what, four in the morning? Besides, they had barely spoken two words to each other back in the precinct.

Sighing, Kate consciously tried to slow her breathing as she untangled herself from the blanket, climbing into bed.

That dream felt too real for her liking. After so many years, the thought of Castle, let alone Castle in danger, still sent her heart into a frenzy.

Maybe it was returning to New York, or maybe it was seeing everyone again, or maybe it was 3XK's threat – but whatever the trigger was, her brain had been scattered and jumpy ever since the call to fly to New York.

Kate's mind flew to another conversation she had with Deputy Director Freedman three years ago.

She had been sitting in her car, about to walk into the playground and share the news of her decision with Castle. Just a few more minutes, and Castle would get to hear her news. She just needed to sit patiently for a while more as her call was transferred to the right office.

"This is Deputy Director Freedman speaking."

"Good afternoon, sir, this is Detective Kate Beckett from New York, thanks for taking my call. I've made up my mind. While the offer is very tempting and a great honor, I'm afraid I'll have to turn it down, sir. I belong in New York, with the NYPD."

"I'll be honest, I'm disappointed. Detective Beckett, I was hoping for better news. These opportunities rarely come in life. Are you sure about your decision?"

A small part inside Kate wavered. The offer really was very tempting.

But she had made up her mind. Staying in New York with the NYPD was the right choice.

"I'm sure, sir," she said firmly.

Kate heard Freedman sigh as a soft creak in the background traveled through the phone. Perhaps he was leaning back in his chair?

"Give me five minutes and listen to what I have to say, will you? I want you, Detective Beckett. You have so much potential, and we can train you to be an exceptional agent, one of the top in the field. But you know that already. I actually wanted to get you on board to lead our 3XK team due to your background expertise on him."

"Sir?" Kate asked, confused. This had definitely come out of left field.

"As you know, his body was never found, and we believe that he is still alive. We've been keeping tabs and monitoring activities that we think could be related to Tyson. The closest anyone has ever gotten to him was in New York, and both times were by your team."

Kate knew all that, but what was his point? Where was this all heading?

"At least join the federal task force on a trial basis. We'll train you, and you can lead the 3XK team. Whatever you want, whomever you want, we will try our best to accommodate you. And once we catch 3XK or if the trail runs cold for 3 months, you're free to decide if you want to stay on or go as you please. Just don't turn down this opportunity without giving it a shot first."

"Whomever I want, sir? So I can have my team along? Even my partner?" Kate asked, intrigued by the new offer.

"Come down to DC for your training. In 3 months you'll be done and you can lead the federal team. If you still want your current team on board, I'm sure we can work something out with the NYPD. Regarding Mr. Castle,"

Kate sat up, straining to hear his next words in anticipation.

"While the federal task force rarely, if ever, allows civilian consultant, we will allow his presence on your team as long as he signs off on all the waivers. But you should keep in mind, detective, this time round, we're going after Tyson. We'll be hitting him before he has the chance to strike. It will be a lot more dangerous than before. There's one last thing you should know. Tyson remains unaware that we're on his trail, and we'd like to keep things that way, so the real reason for your recruitment needs to be kept to a need-to-know basis, alright?"

"I understand, sir. Can I have the day to think about it? I'll get back to you tomorrow."

This was even better than the job offer. She could go to DC and go through with the training – surely that will only help her hone her skills – join the Feds on a trial basis, and if she didn't like it there, she could always return to the Twelfth.

The boys wouldn't feel the sting of her three-month training absence if she could bring them along when she led the investigation.

And Castle – Castle would be a part of the decision making process this time. She'd bring this idea to him and see what he thought of it.

"Very well, detective. I'll be waiting for your call tomorrow. This is the best that I can offer you, and if it still isn't enough, we'd have to go for someone else."

Kate hung up, slipping her phone into her pocket as she crossed the playground, spotting Castle almost immediately. She made her way over to their swings, sitting down beside him.

She couldn't wait to share the news of Deputy Director Freedman's new offer with him, but first she had to apologize.

Kate remembered how her apology had been cut short by Castle and what he'd said about her keeping secrets and thinking about where their relationship was headed.

It felt as though time slowed down with each word being dragged out of his mouth.

"I've decided I want more. We both deserve more."

Their possible future flashed in front of Kate's eyes. Attending Alexis' graduation together, eventually getting married, growing old and grey together.

They couldn't have that if Kate went to DC. It would be too risky, putting Castle in danger like that.

He wouldn't be able to lead a peaceful life, going from state to state, chasing after Jerry Tyson's shadow. He deserved more than that.

He also deserved the peace of mind from knowing Tyson was finally caught; knowing that he was finally safe from Tyson's reaches.

"So whatever happens, whatever you decide, Katherine Houghton Beckett, will you marry me?"

Her mind went black as every single thought she'd had flew straight out the window. Any possible answers died on her lips.

She couldn't bring him to DC. After all that has happened, he still wanted to marry her. He deserved better. More than anything, he deserved happiness and peace for his dreams to grow.

And she couldn't give him that.

"I…"

The words remained stuck in her throat.

She had to turn him down. She had to give him a shot at happiness.

But a part of her remained selfish. She wanted him for herself.

They say if you really love something, you should let it go.

Kate never really understood that line until that moment. She was about to make the biggest sacrifice in her life for the man that she loves.

Kate just hoped that he would eventually forgive her.

"I can't."

She saw the lights die in his eyes.

It was all a blur after that – putting on a mask, keeping her tears at bay. Collecting her things from his place, the hasty goodbyes and evading everybody's questions.

Somehow, she managed to call Deputy Director Freedman to confirm going to DC. Before she knew it, her training had begun.

Initially, she still called Lanie to keep in touch, but it was hard on the both of them because of how she ended things with the boys. No one apart from her dad knew the real reason she went to DC, and Kate had sworn him to secrecy. If she were to have a real shot at getting Tyson, she couldn't afford him finding out that she was on his trail.

Eventually Kate stopped calling Lanie because the timing was never right anyway. Either Lanie or Kate would be busy whenever the other was free to talk. Before they knew it, one thing had led to another and Kate had severed all ties with New York.

In a few months' time, the 3XK trail went cold, but Kate decided to stay on and work cases with the Attorney General's office since she had burned her bridges back in New York. She was focused and determined, solving complex cases. Special Agent Kate Beckett quickly became a rising star. Before she knew it, three years had gone by.

That was it. She needed to cut short her trip down memory lane. Kate picked up her tablet to check on her team's sleeping arrangement. Perfect.

She collected her phone and keys, threw on a robe and padded quietly two doors down the empty corridor.

Kate knocked on the door lightly – he had always been a light sleeper. Soon enough, the door opened.

"Kate?"

He had never turned her away before and Kate was counting on that. She needed a distraction – something to keep her mind occupied.

Wordlessly Kate stepped into the room, shutting the door firmly behind her.

A/N: Review? Pretty please? :)