It's lonely.

It's lonely almost all the time. There's the slight reprieve during the day at the precinct, when she's surrounded by people, an endless stream of activity that leaves most daylight hours behind before she even feels like she can take a deep breath.

And being with her team, with her boys, helps.

But it's also a reminder. A reminder that they have their lives, that they aren't set apart the way she is.

They have friends and families and lovers and people whom they let in, whom they spend their time with.

She has the dark. While she yearns for their openness, their happiness, their peacefulness, she also cowers. In some ways, she craves the darkness. Knowing it is, in its own way, safe. Self-protective.

But knowing that he loves her, that the man who works the hardest she thinks anyone ever has to get through to her – harder than her mother when she was struggling through her early teens, certainly harder than her father during the years following her mother's death, and harder still than her father once he sobered, once he realized how badly he had broken everything – is, in its own way, completely devastating.

When she sat on those swings, when she looked him in the eyes and she all but promised him someday, she was sure she was telling the truth. She was sure she could do it. Jump in. Be with him. Start something and then see it through. Forever.

But now she just chokes on the tears that burn her eyes, on the panic that rips through her every night. On the bone crushing desolation that both exhausts her and prevents her from resting.

Chokes on the realization that she was lying to herself. To him.

Chokes on knowing that she's going to break him one day. One day soon. One day when she pulls him aside and asks him to leave. Lies to him, tells him she couldn't love him, not now. Not ever.

Forces him out so he can move on.

This thought, this firm belief, gives her some strength. Makes her feel a little power, a little control when everything around her is crumbling.

Actually. Maybe tomorrow. She'll tell him tomorrow.

Then he can head back towards the light, where he belongs.

And she can be left alone, in her darkness, but at least back to where she only has herself to worry about.

She hates being responsible for someone else's heart when hers is just barely beating.

She gets in early, earlier than usual. She's thought this through. Calmed herself down. Even made her own coffee, as if to reassure herself that she is capable of doing this on her own. Capable of going back in time, back to where she needed no one.

She has it all set out in her mind. How she'll lead him into a conference room. How she'll calmly lay it out for him. How she won't allow herself to crumble in front of him, because that's not fair.

How she'll tell him that she does remember, that she never forgot.

How she'll watch the realization of that hit him, watch him believe that her silence was confirmation of his worst fear.

And then. She'll watch him walk away.

He strolls in, trying to keep a smile on his face. It's been more difficult lately. Watching her fall apart and having to physically restrain himself from going to her has been exhausting.

Reminding himself that she wants this, too, that she is just working, or waiting, or doing anything to move forward, is just as hard, just as exhausting.

He hopes. But this hope is drowning him.

He isn't sure how much more of this his heart can stand. It pumps his love for her through his veins all day, every day.

And then her face, tight with stress, her eyes, so vacant, so far away, herself held so far apart from him, a constant reminder that she's not there. Yet, he tries to tell himself. Not there yet.

Despite all the small steps it felt like they were taking, it seems like the last couple of weeks has taken it all back, ripped it all to shreds.

And he can't help thinking that, if that's all it takes, if the foundation of this is so shaky that it crumbles so easily for her, it might never have a chance to get off the ground.

Still, he hopes. That's his nature, really, to hope, to reach for magic. He just tries to keep it to a minimum.

When he finally makes it to her desk, he notices immediately that something is off.

Oh. She's made her own coffee.

His heart sinks. This doesn't bode well.

He clears his throat to get her attention, and she is slow to react. Slow to drag her eyes to his face.

His gut twists.

He knows better than to sit down in his chair. He knows better because he can read her. And he can see her pushing him farther away.

"Hey." Her voice is soft, but raspy. From lack of use or lack of sleep or abundance of tears, he can't be sure. But it's not good.

He's silent a moment too long. He knows. He takes a deep breath, puts down both coffees.

"Hey." He manages to push that sound through his lips, tries to twist his lips into a smile.

Her responding grimace tells him he didn't do such a good job.

She's suddenly standing. "Can we talk?"

Time slows down. The air thickens. He can't swallow past the lump in his throat.

He can't respond, just follows her as she heads for the nearest conference room.

He knows better now than to hope.

Once he's past her, she shuts the door. The soft click of it snapping into place helps somehow.

The closing of a door. That's what she's doing. It's simple, really. Just a nudge and it falls into place. She can do this.

He isn't sitting. She wants him to sit. But she doesn't want to sit herself, doesn't want to lose power, so she can hardly ask him to do it himself.

"Beckett, are you. Um. Ok?" The sound is so forced, and the Beckett so obvious, that her chest tightens. Her scar burns.

Kate, I love you. I love you, Kate.

"Yes." She pauses. "No."

He drops into a chair.

"We need to talk." It's the most clichéd sentence in the universe, she thinks. She's sure he would have something better, something more eloquent to say.

To the extraordinary KB.

"Oh." That's his only response. It looks like he's already given up, left all his beautiful words behind.

Good. That's good. Easier.

"I don't think you should be here anymore." She forces the sentence past her lips, hopes it sounds as firm as she needs it to.

Against her better judgment, she looks at him. He looks like he's crumbling, crumpling into himself.

She can't breathe.

But then, he's not. He's fortifying himself. He must realize she's not done.

And she's struck by the harsh realization that she's done this to him. That where he was once full of light, full of joy, full of hope, she's made him hard. Shuttered. Closed off.

She hopes that she's not too late, that he can salvage some of his old self back after this.

"From the precinct?" He finally finds his voice, it seems. The glimmer of hope, the clear thought that maybe not her life, just her job, is obvious, despite his attempt to hide it.

"No. Well, yes. From the precinct. But I mean anywhere. You shouldn't be anywhere anymore." She forces air into her lungs. "You shouldn't be with me."

"I was never with you." She raises startled eyes back to him, notices how even he seems surprised by that. But he doesn't backpedal.

She wants to joke. She wants to say semantics, Castle. She wants him to smile.

She wants to smile.

But she reins it in. No smiling for her. She doesn't deserve it.

"I know." She's surprised by the tenderness that she's infusing into her voice. That's not even what she wants. She wants it to be solid, firm, unbending. Not soft.

"So, what then? You want me out of your life now? You hit a bump in this road you're on, and you're going to kick me out. Going to punish us both." Those are statements, not questions.

She didn't anticipate a fight. He never challenges her. The times he has, he has been booted out. He seemed to learn his lesson.

Maybe this time he can see that his fate is sealed.

This momentarily unbalances her. But then. She collects herself. Remembers the plan.

Go in for the kill, for the sucker punch that she's sure will bring a swift end to this.

"I heard you that day." He immediately looks up at her, his shock betrayed by the flash in his eyes before he manages to school his features. She knows she needs to say it all, to pound this through his skull. "I heard you say you loved me." A pause. He looks like he's going to say something. "I never forgot." She answers the question before it makes it across his lips.

She watches him literally fall forward, watches as her words hit him hard the stomach, watches the air whoosh out of his lungs.

"I'm sorry. I should have told you. But I couldn't. I can't." She is intentionally being ambiguous. She knows she means I couldn't face it right then because I was so broken and I can't really believe that I'm doing this, that I'm throwing this away. But she means for his interpretation to go the other way. I can't love you.

"You won't." His voice is solid again, and she finds that he's straightened.

He's standing. For a moment, she expects to find a challenge in his eyes. What she sees is worse.

It's defeat.

"Ok, Kate." The gentleness of his voice, the use of her first name, sends her stomach free-falling through space. She grips onto the chair in front of her, determined not to let him see her fall. He doesn't need that vision, doesn't need to hold onto the belief – the reality – that this is killing her, too. "I won't do this to you anymore."

That hits her sharply. She falls forward a little more.

But what he says next is so broken, so completely gut-wrenching, that it takes all of her strength to wait until the door closes to fall to the floor.

His voice, so soft, so strained, he whispers two last words to her.

"I'm sorry."