Kate Beckett finished reading her letter for the countless time and folded it in quarters, placing it in her pocket. She thought about her life. So many missed opportunities for happiness, and for what? Her job. Her job kept her up nights and made it impossible to relate to a man in a healthy relationship. At least it had, until Castle. Her job had been what brought them together and had kept them together, with few exceptions for the better part of three years. She looked over at him, sleeping in the first class seat next to her, and couldn't look away.

No one in the world knew her like he did. No one understood her… except for him. As much as she griped about his continued shadowing, she had come to rely on it. She welcomed it. Truth be told, she needed it. She watched his mouth move slightly in his sleep. She needed him, she realized.

How many times had she gone to him for his counsel? How often did she call for no other reason than the need to hear a friendly voice? How many times did the mood of her entire day turn around with his placing a cup of coffee in front of her and sitting in "his" chair next to hers?

When he had been gone for the summer, she had felt as though she would never enjoy her job again. That fact had annoyed her then; now it revealed so much to her. Their relationship was, quite simply, the most important of her life. Not only did she count on him professionally, but she needed him personally. She wanted him near her.

Kate looked at him, lingering on each feature of his face, loving the feeling of warmth that spread over her. She gave his lips a lingering look, remembering the way they felt against hers as they tried to rescue Ryan and Esposito. If their mission hadn't been so important, if the lives of their friends hadn't been on the line… she wasn't sure what would have happened. That wasn't true. She was pretty sure she knew. She smiled at the mental picture, warming even more, sure she was blushing. At least Castle was asleep, she thought.

Why? she asked herself. Would it have been so terrible for him to see how she looked at him? For him to see how much she loved him? How much she loved him. She took a deep breath and sighed softly. It wouldn't be terrible at all she admitted, thinking of what it would be like to press her lips to his as he slept. Instead, she placed her hand on top of his, mingling her fingers softly with his, unable to keep her thumb from tracing circles gently on the back of his hand.

Kate felt a rush of nervousness as Castle's hand moved, his fingers tightening around hers. She watched as his eyes opened slowly, not ceasing to stroke his hand. Castle watched her thumb for a moment before bringing his eyes up to meet her gaze.

"That feels nice." He whispered, afraid to break the spell, the way it had broken their first night in the hotel suite. When Kate didn't say anything, he hesitantly raised his hand to her, cupping her cheek in his palm. His thumb skimmed across her lips, barely touching her skin. She closed her eyes, her breath quickening, and kissed his thumb. When she opened her eyes, she was stunned by the passion she saw looking back at her.

Kate reached out, touching his face the same way he was touching hers. Her lip trembled slightly as she fought the last bit of trepidation.

Castle just waited, for an eternity, it seemed. "Kate…" He covered her hand with his and kissed her palm.

Kate started to reply but rather than words, she responded by leaning over and kissing him. This kiss wasn't frantic and searching like the one they had shared previously. This kiss was slow and deep, wrought with the passion, hidden for so long.

Castle moaned softly as he wrapped her in his arms and deepened the kiss. When they parted lips, he kept his just inches from hers. "Oh, Kate." He said in a shuddering breath, kissing her again.

Kate suddenly became aware of a few other passengers trying to keep from watching. "Castle," She placed her hands on his chest and pushed him back slightly. "People are looking."

"Do you really care?" He kissed her neck sensually, his hot breath coming fast against her skin.

She closed her eyes and shook her head. "Nope." As he kissed behind her ear, she melted back against the seat and sighed. "Oh my God." She whispered.

Just as Castle kissed his way back to her mouth, the pilot turned on the seat belt sign and announced their decent into Laguardia. Castle groaned and sat back against his seat, keeping her hand firmly in his.

"What's the matter, Castle?" She smiled.

He looked over at her with an intensity that made her pause. "Will you do something for me?" He asked.

Kate raised an eyebrow, trying to make light. "I guess."

"Promise me that once we're back in New York," He leaned toward her. "Promise me that I can still kiss you like that."

Kate smiled, relaxing.

"Because if I can't touch you," He leaned over and whispered in her ear. "I will go completely crazy."

"We wouldn't want that to happen." She whispered back, allowing her lips to brush his ear.