Because contrary to popular belief, I do know what a happy ending is (my favourite review of the first chapter included the quote 'Ah yes, sugar free. Killer of moods.' which I don't think was intended as a compliment, but amused me anyway).
This is super clumsily written because I rushed through and don't have the time to edit it to perfection. Any glaring mistakes please let me know!
She goes back to her life. Mourns the loss of Royce and pays her respects to Montgomery, the man who she had hoped would soon be her captain - had been her captain, not that she remembers. Adjusts to Detectives Esposito and Ryan. They care - not like she does, but they do. Hardworking, good cops. She likes them. It's strange, being the senior detective on her team having jumped straight to her goal without all the steps in between but she relishes it.
She works and she sleeps and she eats, and she thinks she's happy.
In her spare time she reads the Richard Castle books that were published in the eleven years she's forgotten. Somewhere in the dog-eared pages of the Nikki Heat series her heart finds something once familiar. Suddenly she's aware of the dark chasm in her chest, realises she's lost something utterly essential.
She remembers first.
He goes back to his life - but it's so different. He comes to terms with the end of his marriage, eventually. With the aid of scotch, and of cathartic tears. He pounds out his frustrations on the hard tarmac of running paths in the parks. He spends hours watching home videos of the years he missed.
He finds himself lost in this world - only nine years passed, yet in some ways it feels a hundred into the future. He'd just gotten used to USB flash drives, for heaven's sake! What the hell is an 'iCloud'?
So he immerses himself in this new technology, comes to love it eventually. Channels his energy into bringing himself up to speed with what's gone on in the times he's lost, almost living in the archives of the New York Public Library. On his way out, he can't help but look up at the shelf where his own books sit - the ones he can't bring himself to read, unable to recall ever writing them.
It's there that an overly-rambunctious child sprinting past him collides with the rows of books - and slowly, ever so slowly… A hardback edition of one of Rick's own novels trips down the shelving, until it hits him, the corner smacking solidly into his temple with a thunk.
It's maybe half an minute later that his eyes blink open, a few worried faces peering into his line of vision.
"Kate?" He asks. He's not sure why. He frowns, confused and then - oh. As he sits up carefully, his gaze slides to the hardcover next to him. Deadly Heat, stamped across it in bold.
He remembers second.
She remembers in dribs and drabs - in the phantom touch at the small of her back as she steps in the elevator, to the sudden desolation she feels opening the door to her apartment. Expecting chaos and fun yet encountering a cold calm, which, once comforting, now just feels - empty.
She remembers in the blue of the sky - the way it reflected in his eyes as she held his hand in the park.
She remembers in the warmth of the sunshine - lying on the beach, tucked into him as they bask in the rays of light.
She remembers in the delicious bitter-sweetness of her coffee - feels the brush of fingers over hers every time she grasps her mug. Heart aching unbearably when the taste of it lacks the love she's not quite sure why the drink represents. But it does, she knows that for sure.
She's so confused, these days. How can she miss a man that she still doesn't know, not aside from the ghost of his presence that trails after her?
It doesn't make sense, but she does.
She shuts her eyes against the sour disappointment that comes after every memory fades, just before she can grasp it. Wishes desperately for another; she's come to crave these tiny flashes in her mind, where there's him.
He remembers all at once. Ignores the concerned admonishments of the library staff ('Sir, you could have a concussion!' 'I really think you should go to the hospital, Mr. Castle.' 'At least wait for the paramedics! They're on their way') as he scrambles away. He finds an empty bench in Bryant Park and collapses into it, the onslaught of memories exulting in the relative privacy. They come quicker and clearer, now.
He remembers.
The song of her laugh - in the precinct, in the loft, in the Hamptons… wherever they are, he exults in that sound. Needs to hear it again, right now.
That closed-lipped smile, a thousand secrets behind it that only he is privy to. The midnight confessions she breathes against his neck at night, curled into him, one hand resting over his heart. It beats for her.
The look - when she's jealous, or annoyed or unimpressed and she lets out that little hmph of hair and it's - she'd kill him for saying so, but God it's adorable.
It's almost too much, nine years of memories raining down on him and
-oh, Alexis.
His little girl growing up - he has it all now. Crying over haircuts, and playing laser tag. The first crush she refused to speak about but caused her cheeks to flame fire-engine red. Starting high-school, and finishing. Everything in between.
He loves her so much. Needs to see her, and now.
A quick text to check she's home, and then he's hailing a cab. Chucks fifty dollars at the driver and promises him the same again if he gets to Broome Street quickly.
They make it there in half the usual time and Castle makes good on his promise. Chucks a good afternoon, Eduardo! over his shoulder as he races to the stairs. Too much energy to wait for the elevator right now.
He bursts through the door the loft and sweeps his daughter up into his arms.
"Dad?" Alexis lets out breathlessly, squeaking slightly as he squeezes even tighter. "What-?
"I remember, baby bird. I remember - everything."
And then they're both crying, because God, it's been hard. It's a while after that, laughing and tearing up over the memories he suddenly has back that she asks the question that's been gnawing at the back of his mind.
"What about Kate?"
He pauses for a long moment. "I need her, pumpkin… I'll do whatever it takes to get her back - but I'm scared she won't be her anymore. She doesn't know what we've been through, but I - I have to try, Alexis."
His daughter looks at him with those wise blue eyes, and smiles softly. Gently, with a smooth curl of fondness at the corners. As if that's what she expected him to say. As if she finally has her father back. "Go, Dad."
She breaks on a sunny Wednesday afternoon in mid August. Can't stand the stifling heat of the precinct so she just - leaves. No word to Gates, no regard for the half unfinished pile of paperwork on her desk.
She's not sure where her feet are carrying her until she stands in front of a building she can't recall ever visiting before but feels like home.
And suddenly a new flood of memories hit her:
Sleepy and a little tipsy, being carried inside in strong arms. Safe and warm and happy. In love.
Bone tired and aching from a vicious case, and how she'd taken out the stress of the day on an undeserving punching bag. A delicious balm soothing over her burning joints as she steps into the building, one step closer to her favourite occupant.
Dripping wet and shivering, raindrops mixing with tears as she stumbles to the front doors. Fear and need and desperation. For him. All for him.
And - oh god oh god oh god - there he is.
"Castle."
His name tumbles from her lips like coming home and the word tastes so good in her mouth, she says it again. Louder this time. "Castle! Castle."
He looks to be in a rush, but he turns at the sound of her voice. The magnetic pull she feels now tugging them together.
"Kate." He says, and it's breathless and slightly confused. Full of a joy that feels right, that wakens something in her she didn't know existed. It bursts open and she loves him, this man that she barely knows. Loves him so much that she doesn't want to go without him ever again. "Kate!"
She collides with his chest before she even realises she's moved towards him. Wraps her arms around his torso, breathing in the scent of him.
"You remember?" She hears him ask. Nods uncertainly against him.
"Not everything - but you. I remember you."
It's oh-so-easy yet the hardest thing they've ever done.
She remembers more and more everyday, from tiny details to things that nearly shattered them.
He holds her as she remembers how she loved her captain, how he died to save her. How she nearly died anyway. Gives her what she needs as she deals anew with the PTSD and the shooting, whether it be space or comfort. Insists she's forgiven when she apologises for those months after where she left him without a word.
She reels when she recalls who killed her mother.
He stops her from falling down that rabbit hole.
And one day, one crisp clear winter morning - once they're them again... He gets down on one knee, and offers her the same ring she'd left in his hospital room that day. He hadn't known why he held onto it at the time-
Fate, she decides, mumbling the words against his lips as he pushes the diamond band onto her finger. "I guess we're just meant to be."
I am aware that bumping your head a second time does not cure amnesia... But I may have watched The Muppets Take Manhattan while babysitting this week, and used that.
(I don't own Castle. Or The Muppets, for that matter).