"Kate...I can explain," Rick replies quickly.

"You'd better freaking hope you can." Kate yells angrily, her New York accent thick. She rolls out of bed and runs her hands down her sides to straighten her clothes, exhilarated yet horrified at what nearly just occurred. Running her finger along the screen, it's immediately obvious to her what she's looking at.

"You've...you've...you've been investigating my mother's murder? Without telling me?" She gasps, choking back a tear of betrayal. Just as she thought everything was perfect between them, he'd done this. This...bordered on unforgivable.

"Kate..."

"Castle. You've been looking into my mother's murder. After all we've been through. After everything that's happened? How could you do this again?" She answers meekly, feeling weak and betrayed.

"Kate."

"Don't."

"Don't what?"

"Don't call me Kate. Like we're partners. Like we're people that share everything. Like we trust each other. Not after this."

"Beckett...let me explain...it's not – "

"Castle, let me save you the drama. I'm done. It's over." Beckett exclaims as she walks out the door, slamming it behind her.

"What it seems – " Castle finishes, talking to no one but himself.

Castle stands for a moment, dumbstruck. The reality of the last 4 years hits him, and he realises that he's closer to her then he's ever been, and he's not prepared to let that slide. He's not prepared to give in just yet,

Chasing after her, Castle runs out of his apartment and takes the stairs. He gets to the lobby and hears the elevator chime.

Positioning himself in front, he prepares for a showdown.

The doors chime, and Beckett is revealed, looking hurt and demoralised.

"Kate,"

"No."

Roughly, he grabs her elbow.

"Kate, I'm not giving up this easy. I know you're strong, but listen to me. Give me a chance. Give US a chance." He pleads.

Shocked at his declaration and perseverance, she relents.

"What, Rick? What can possibly explain what I just saw in your apartment?"

"Beckett. C'mon. There's a reason you were shot. There's a reason for every single thing that's happened. I know I should've explained it to you...but...I was warned."

"What do you mean, warned?" Kate exclaims defensively.

"You were shot Kate. The...(he chokes on his words...) the...woman I love, was shot right in front of me...I was scared for you..." Castle chokes on his words.

Kate stares at him, angry but also understanding.

"I was called," he continues, "after you were shot, I was told to stop you, to let it lie. I wanted to protect you Kate. If something were to happen to you... But I also wanted to find justice for you, justice for your mother. But I knew you wouldn't listen...that'd you'd find a way to fight this warning."

"Damn right I would Castle," Kate cries out, tears in her eyes. "How dare you decide what's best for me? How dare you decide what I know!"

Castle grabs her arms and prevents her from turning away. He holds her in place and stares into her eyes.

"Kate, I didn't do this to intervene. I didn't do this to stop you from finding out about your mother. I did this because I'm selfish...because I couldn't bear to see you in danger...because it would kill me if I lost you. The moment you were shot was the scariest moment of my life. I know it doesn't erase it, but I kept it from you to keep you safe. To keep you with me."

Kate allows herself to relax for a moment in his grip, and Castle feels some of the tension disappear from her body.

Sighing, she leans her forehead against his chest, allowing him to swallow her in his arms for just a moment, before putting her hands on his chest and pushing herself back.

"Rick...I get why you did it. But I just...I just need some time okay? I need a moment."

"Kate," Castle exclaims softly, taking hold of her hand. "Please don't let this erase everything..." He pleads.

"I'll talk to you later, okay?" Kate replies sadly, turning around and letting her hand drop from his.

Castle is left standing alone in the lobby, as Beckett walks out of his building, and out of his life.

A few hours later, Beckett has calmed somewhat. Though that may also be due to the two wines she's knocked back whilst chatting to Lanie at the bar.

"It's just never straightforward with you two, is it?" Lanie jokes, leaning her arm on the counter.

"I just feel so...betrayed." Beckett sighs, gulping down another sip of wine.

"Kate, I haven't watched the two of you dance around each other for four years, to have you find a reason to end it just as you were accepting it." Lanie says firmly.

"But he –" Kate starts as Lanie cuts her off.

"Yes, yes, I know. He kept this big huge secret from you. I get it. But what I don't get, is from what you've just told me, you kept the poor guy thinking you didn't know he'd professed his love for you. You've got some crazy double standard going on here." Lanie replies strongly, not giving Kate a chance to back out of the conversation.

"That was different, I –," Kate tries as Lanie cuts her off again.

"Yes, you weren't ready to let him know how you feel. You were scared. But Kate, everything is out on the table now. It's do or die time. And as far as I'm concerned," Lanie continues, her voice losing some of its seriousness and taking a softer tone, "The man was willing to put a target on his own back in order to protect yours, and that's something that is okay by me. Don't back out now Kate. You deserve to be happy."

As realisation dawns on Kate, she allows herself a small smile and takes a final sip of wine.

"Thatta girl." Lanie laughs, understanding the her point got through to Kate. "Now," she says seriously, handing Kate a shot glass, "take this tequila shot with me, then march yourself back and put that man out of his misery."

Smiling, the two friends clink their shot glasses together and each downs the shot.

Slowly, Kate stands and grabs her jacket. She places a hand on Lanie's shoulder.

"Thanks, Lanie."

"Anytime. At least one of us should be getting some action." She teases.