It was their first day back together since Castle had left with Gina for the Hamptons. Beckett had done her best to avoid him, making small talk only when necessary. Tension at the precinct was high. Her friends around her had all witnessed the heartbreak on Beckett's face as Castle walked away from her on his last day, locked in an embrace with his ex-wife. She meant to tell him everything; to apologize for being so oblivious to his feelings, to let him know how deeply she cared for him, how she didn't want him to leave. But she was too late. Beckett spent the rest of the summer haunted by thoughts of Castle and Gina's rekindled love. How would this affect the novel? Was this going to be the end of Nikki Heat? But Castle came back to her. Surely that had to mean something.

Their case was at a complete stalemate. There was a piece missing and no more progress could be made until they found it. Someone was lying… But who? Beckett packed up her things and got ready to head out. She wasn't getting any work done, and having Castle's summer looming over her shoulder was nothing but a distraction. She needed to go home and clear her mind. She needed an escape.

"Kate, where are you going?"

"Home." Beckett kept it short and simple. She was sure not to let down her walls for him again this time, not wanting to let him catch a glimpse of the pain she had gone through that last day together. Beckett was not one to wear her heart on her sleeve, and she realized she had made a big mistake opening herself up to Castle in the first place. A mistake which she would not make again.

"Wait! I'll come with you. I'm sure Alexis is worried about me anyways." Castle frantically rushed to grab his things and jogged to catch up with her at the elevator. They stepped into the elevator, standing together in silence. Castle sensed the hostility in Beckett's presence. He turned to look at her and saw something strange in her eyes; something he hadn't seen since he opened up her mother's case again. Not quite anger, but sadness. Quickly stepping forward, he stopped the elevator.

"What the HELL are you doing, Castle?"

"Kate, what is going on? You have barely spoken to me all day. Is everything okay? Did I do something? I thought you'd be happy to see this ruggedly handsome face after a whole summer…"

"Is everything a joke with you?"

"…Kate."

"I left him, Rick."

"What? Left who? What are you talking about?"

"Demming. Everything changed when you told me you were leaving. That's when I realized…. Nevermind. Let's just go. Please." Beckett reached for the emergency stop on the elevator. She needed to get out, and she needed to get now. The room was getting smaller. It was becoming harder to breathe. She had barely just begun to face the facts herself, she was not about to open herself to Castle again just to get hurt once more. Castle gently grabbed her wrist, stopping her from running away from this conversation. Not letting go, he pleaded with her.

"When what, Kate? Tell me. I'm begging you, don't shut me out."

"That's when I realized… I cared for you too."

Castle's eyes widened, his mouth opening slightly, begging for the right words to say. For once, he was speechless. Kate stared at him, searching his eyes for a response. His silence unnerved her and she instantly wanted to take back everything she had just spilled onto him.

"… But you're with Gina now. I'm sorry, I shouldn't have-" Castle hushed her mid-sentence, placing a finger to her lips. Still holding on to her wrist, pulled her in close. He gently caressed her cheek, looking her deep in the eyes. This was not the Beckett he knew. He had never seen her so vulnerable, so open. He felt a strong urge to protect her, though he knew she was perfectly capable of taking care of herself. Slowly, he lowered himself to her as they leaned their foreheads against each other, both hesitating slightly before softly brushing their lips together.

Kate broke away "…Castle. what are we-" he once again silenced her with a kiss, this time deeper and more passionate. Kate ran her fingers through his hair, urgently pulling him closer to her. Castle tightly locked his arms around her, kissing her forehead and breathing in the sweet fragrance of her hair. "Oh, Kate…" He quietly murmured. They separated themselves once more, flipping the emergency switch of the elevator and continuing on their way down to the parking garage. Castle walked Kate to her car, resting his hands on her hips and kissing her cheek.

"If you want, we can go back to my place for a drink…" Kate said, though both knew the real reason she wanted Castle to come back. After ignoring each other's feelings for so long, it was finally time to stop denying their chemistry.

"Do I get to drive?"

"Hah! You're a funny, Castle. Anyone ever tell you that before?"

I realize this is not how his actual return went, but as I said, I wrote this awhile ago. R & R, but be gentle. It's my first and probably only fanfic.