Author's Notes: This isn't a post ep so much as an insertion scene toward the end of the episode (you'll know fairly quick where in the episode this takes place.) Thank you, Holly, for the help!

She stands in the shadows watching him.

The clench of his fists; the long, strident steps as he paces; the almost unnatural way he carries himself, spine straight and posture impenetrable. She finds herself opening her mouth and then closing it, the words longing to escape but silence wins. Not even Castle himself would be able to find words in this situation and she takes a step forward. If he notices he doesn't say a word, just like he didn't when the door to the stairwell slammed shut, and she doesn't know how to do this, how to calm him like he's done for her so many times. The jokes he'd once made in times of sadness seem too crass and the soothing words die on the tip of her tongue.

The farmhouse is empty.

The one lead they had is gone and they're back at square one, his daughter somewhere out there. She knows it doesn't take a writer to imagine the worst, not when she's spent over a decade delivering bad news, when she herself had once been on the other end. The scar between her breasts aches and she presses her hand to it, feels the erratic beating of her heart.

"Castle." It comes out ragged, a mere whisper trapped inside cinderblock walls.

The pacing stops and he looks up at her, stealing her breath away. He's no longer the man he was when he walked into that precinct a little less than five years ago filled with mischief and childlike excitement. He's one of them now, not just bogged down with the fictional death he writes about but with the bodies that have piled up over the years, families who have suffered, parents gone and children lost. She sees it in his red rimmed eyes; the fear that he's in a club with all the parents whose lives had forever changed. The ones they had given empathy to over the years without ever fully understanding.

Kate takes another step closer, clearing her throat. She's close enough to see the tears that pool but don't fall, the sorrow and lost hope. "I spoke to Harris. His team is going over every spare inch of that house. If they left anything behind, we'll find it."

He stares at her and she almost wonders if it's registered, if he's here with her or back in that room nineteen years ago on the day that his daughter was born, inexplicable love that has made him the man he is today. She keeps her gaze focused on him, watches him blink back into the present, head turning until he's no longer looking through her but at her. A chill runs down her spine at the emptiness that resides, and she's petrified of what's going to happen if –

No. Alexis will be fine.

They've dealt with worse, arrested murderers with less.

"Like we found Alexis and Sara?" It takes her a minute to realize that he had heard her, that the anger that penetrates his words is the same man she's been in love with for years, the same man she's spent the last nine months dating, building a life with. "How do we even know they were there to begin with?"

"Stevens told you-"

"And kidnappers never lie, Beckett? He would have said anything to get me to stop."

Kate thinks of the screams that had come from that room earlier. She had been conflicted, concerned and yet not all that surprised. She had seen the damage done to Castle's hand after he attacked Hal Lockwood in that warehouse, the fierce strength he had when dragging her out of that hangar. He bled for those he loved, played the hero more times than she can count. "The FBI know-"

"Don't," Castle snaps, the rage in him an odd counterpoint to the lifeless shine in his eyes. "Don't tell me again that my daughter is in the best possible hands when we have no idea where the hell she is. This was all we had, Beckett, and now it's gone. She is gone and you and the FBI have no fucking idea where to even start looking."

The muscles in her heart clench, nearly cutting off oxygen. It's too familiar and too broken and she thinks of her mother, of all the times he had been strong for her when she needed it the most. She wants nothing more than to wrap him in her arms, to calm him, but he's pacing again, scuffing worn floors, knuckles white with anguish. "You've been to hundreds of crime scenes. There is always something left behind. We will find another lead. No one out there is giving up. Alexis is one of ours, Castle. We're all fighting for her."

"What if it's not enough?"

She closes her eyes for a second, takes in the stilted air because what if has been in her mind all afternoon, a constant palpitation of broken promises and lost lives. "I don't know," she responds honestly. "But right now it has to be. Right now we fight. We search for answers. We do our jobs."

Castle stands one step below the landing, bracing his hands against the wall. He leans his head against the cold block and even his broad back and wide stance don't diminish how small he looks right now, broken and battered and merely pieces of his former self. She walks closer, sliding her hand over the curve of his spine. She hears the rattled exhale that escapes him just as his palms fold over, nails digging into his hand. His knuckles rap on the wall, constant and bruising.

"She's out there, Kate, and there's nothing I can do to protect her anymore." The anger has diminished in his voice and it's hoarse like he's been yelling for years with no one around to hear. "I wasn't always the most responsible person, but Alexis grew up knowing how much I loved her, that I would have done anything for her. I have two marriages that didn't work, books that haven't made it to number one, an arrest record, but none of it mattered because I had her. I wasn't a screw up to her like I was to the rest of the world. I did right by my daughter. I was her knight in shining armor. And now I've failed her and there's nothing I can do to fix it. I can't be the man she thought I was."

"Look at me." It takes him a minute, long enough that she thinks she's lost him, but then he lifts his head, turns his body away from the wall so he's facing her. She slides her hand down his arm and reaches for his hand. It's a perfect fit in hers, the grasp tight, almost painful. "You are the man you've always been. The same man who turned the loft into the Star Wars galaxy on Alexis' sixth birthday and let her wear her Princess Leia costume for the next week because she felt like royalty. The same man who wouldn't hand over his daughter to a nanny and spent every afternoon in the park with her. You're the father who every one of your daughter's friends wishes they had. You are not a failure, Castle. You will never be a failure when it comes to Alexis."

There are tears running down his cheeks and god, she wishes she could do more, be more, help more. She wipes them away with the pad of thumb, soothing and gentle, and pulls him closer. The toes of his shoes hit the step and he's cracking at the seams, shoulders shaking, shattering piece by piece.

"Come here," she whispers, and then he's wrapped around her, arms banded around her waist, face pressed between her breasts as he quietly sobs. She combs her fingers through his hair, closes her eyes as his muffled cries hit her skin.

There's so much she wants to say to him: we'll find her, I love you, I will do anything to protect both of you, but none of it is right – not now. He's shaking against her and she presses a kiss into the crown of his hair, murmuring words she knows he can't hear, promises he'd never forgive her for if broken. He's whispering his own pleas against her, desperate cries that make her knees want to buckle and her entire body aches because this is her job and she's still somehow helpless, so incredibly helpless. She squeezes her eyes shut after the fourth I can't lose her, feels the wetness slide down her cheeks. They stand like this for minutes until his body quiets and then stills. He doesn't move, doesn't dare leave her side. His warm breath hits her skin from where her shirt has shifted, deep inhales slowly turning to normal. The grip on her waist loosens and he's backing up, taking another step down, but she sees it, that something returning to his eyes.

Hope and determination.

Fight.

"I'd like to go with you to the farmhouse," Castle says, and it sounds nothing like him and everything like him at once. "If there's something of Alexis' there, I'll know."

She doesn't ask if he can handle it, doesn't try to persuade him otherwise. Instead she nods, "Okay."

Castle meets her on the landing and stands in front of her, tilting his head so their foreheads rest together and she doesn't know if he's stealing strength from her or vice versa. "Thank you."

"You don't need to thank me. We're in this together." She wraps an arm around his waist, keeps him buoyed to her another second longer. She places the softest of kisses against the corner of his mouth. "Let's go find your daughter, Castle."

As always, thoughts are appreciated.