Kate and Martha were standing in the hotel lobby when Castle walked in with his arm around Alexis, his daughter wrapped in his coat. Martha's ran forward with an incoherent exclamation and enveloped her granddaughter in a tight hug, Castle reaching his arms around both of them, lifting his weary head to meet Kate's eyes. He smiled slightly before his face grew serious. Despite the undeniable relief in Beckett's eyes, there was something akin to fury in her face as she looked at him.

When Martha finally released Alexis, Kate walked over and pulled the girl into her arms whispering softly "I'm so glad you're OK" as the girl's body relaxed in her arms. "Dad saved me," Alexis said, her voice catching in her throat as she pulled herself back to glance at her father. Martha swept in between them and placing one supportive arm around Alexis led her to the elevator to their room.

"Kate.." he started before she turned on her heel and walked into a secluded corner of the lobby, knowing he would follow. "I'm..."

"Stop Castle. Just stop. Do you have any idea what you put Martha through disappearing like that? What you put me through?"

"Just let me..."

"No. No explanations. Of all the times I've almost lost you, this is the first time that you deliberately put yourself in harm's way without me by your side. You promised me..."

"Ka-"

Kate put her hand up to silence him and took a deep breath to steady herself. "You told me I'd never lose you. After everything we've been through, how could you not trust me? You and I, Castle? We grow old together and bicker til the end. I cannot lose another person I love." She ended, poking him in the shoulder for good measure before slumping against the wall and allowing the relief of seeing him wash over her.

Castle stepped close to her, shielding them from curious passerby. "Kate..." She shook her head slightly. "Kate," he said more firmly reaching down to lift her chin, bringing them face to face. She still refused to meet his eyes. "Beckett. I didn't think. I couldn't ask you to put your job on the line." She huffed at that and her slight eye roll sent the tears that had collected in her eyes cascading down her face. Castle swiped his thumb over her cheeks, wiping away the tears. "You're right. I'm sorry. I should not have done that to my mother," he ducked his head down, forcing eye contact, "or to you."

Kate smiled weakly, finally holding his gaze. She opened her mouth to say something but seemed to think better of it, weaving her arms around his back and tucking her head under his chin. "Never again," he mumbled into her hair. She nodded against him before leaning back her head and looking up at him. "Let's go get some sleep." He nodded wearily and took her hand, walking together to the elevator.

48 hours later they had tied up the case and were on a flight home, with Castle seated between Alexis and Kate. Alexis was fast asleep, her head on Castle's shoulder. Beckett was holding his hand, tucked against his other side. She glanced sideways at him. "Not mentioning it must be killing you Castle," she teased. "What?" he asked, studiously avoiding eye contact and suppressing a smile. "I meant it you know," she said softly. Castle took a deep steady breath, "Beckett, I have no idea what you're talking about. But I love you all the same."