I had to write this because we all know how protective of Castle Alexis is and I wanted to go into how Kate leaving affected her. This takes place a few months after Kate leaves and Castle's whole "trying to win his wife back" storyline. In this Castle still does not know the real reason why Kate left him but Alexis finds out. I understood her reasoning but I hated that ending.
Alexis needed to do something, she's been watching her father slowly disappear in front of her eyes ever since his wife had left him. She had never seen her father like this before, she doesn't remember what he was like when him and her mother split up, but he wasn't like this when Gina upped and left him. When she left, he felt almost relieved. It's been months since Kate left, with no other reason other than she needed to work a few things out, with the unspoken promise that she would be back as long her father would take her back. Alexis has never been through something like that before but does not know how her father could ever take someone back who has hurt him so deeply.
Kate leaving not only affected her father it had affected her too. She loved Kate, she had become a part of their family and she had been raised to believe you never give up on family, but she doesn't know how to not give up on the woman who broke her father. He doesn't even try to put on a good face in front her, she sees the pain in his eyes and everything he does. Sure he still helps out Esposito and Ryan, but every time he comes home and little bit more of him is gone. She has to try to help her father before he is completely gone. She can see it coming, he has written since Kate left, Gina and Paula have both been calling her because he refuses to answer his phone unless it's one of the boys. She knows Gina calling only reminds of his failures as a husband and makes him worse. The first few weeks after Kate had left, he had seemed to have lost it. The man bought a bow and arrow and shot it off in the loft. He seemed to temporarily resort back to his "playboy" ways minus the sleeping around, but she knew he was just trying to hide his pain. But one day something had happened, he had come home from the precinct, and it was like he had given up hope. She was not able to get anything out of her father as to what happened. So she went to the only source she could, her estranged stepmother, those were words she never thought she would associate with Kate the day she married her father, but now here they are.
When Alexis had walked into Kate's office, she wasn't expecting to find her stepmother behind her desk crying. The crying seemed to get worse when Kate realized it was Alexis who had entered her office. Kate asked her what she wanted, Kate was expecting to see her, Alexis hadn't spoken a word to Kate in months, even if she had seen her a few times when meeting her dad with Hayley. Alexis told Kate all she wanted to know was what happened that day, that her father came home a shell and shut himself in his office. Kate told her that her father had seen Demming in her office simply talking to her about a case that homicide was a part of with the robbery department. That Demming had heard that Kate and Castle had split up and was trying to make a move and Castle had walked into the office just as Demming had grabbed Kate's hand asking her to go out with him for dinner. Before Kate could say no, Castle had left out a loud sob and turned around and had fled. Alexis now understood, and she was having trouble controlling her anger. Alexis only had one thing to say before she walked out and that was that they went from happily married to this in only a few months. That in a few months Kate had done to Castle in his eyes, what his first two wives had done to him combined. That as far as her father was concerned Kate had cheated on him with an old flame just like Meredith did and she had come home one day, packed a bag, barely gave a reason why, and had left him just like Gina did. Alexis told Kate that she needed to fix this before she lost her father for good.
Once Alexis left, she needed to talk to someone before going home, that person used to be Kate, but now she turned to Hayley. Alexis had been growing closer to Hayley every time she was in town helping them on a case. Hayley had told her didn't understand what had happened in the short time she was gone but that Alexis could count on Hayley on anything she needed. Unfortunately that conversation had been overheard by Kate at the time and after that Kate had never been able to look Alexis in the eye again. After talking to Hayley, she went home to talk her father about her conversation with Kate. What she wasn't expecting was to get home to an empty loft, his clothes were gone, his laptop was gone, his passport was gone. The only thing left was two piles of paperwork on the kitchen counter. One addressed to her and the other to Kate, with a note asking Alexis to deliver this to Kate. In tears, she opened hers, where there was a letter;
Alexis,
I am so sorry to say goodbye like this. I am failing you as a father and you deserve so much more than that especially from me. Know that I will always love you and once I get my head straightened out, I will come home to you my beloved daughter. You've grown into a very smart young woman, where you get that I do not know, but I am putting my faith and trust in you like you have always asked of me that you are a grown woman and fully capable of taking care of yourself. Our PI business is now yours, I have also arranged for you to have access to your trust fund early. I had it set up that it automatically went to you when you turned 22 but you're responsible enough to handle it now. This is not forever, I will be back. I just need some space from New York, too many painful memories. You are free to join me whenever you wish, I enclosed in this my new address, I will be staying in London for a while. Paula should stop calling you, since I spoke to her telling her that I was ending Nikki Heat on a good note and needed to figure out where to go next. Surprisingly she told me that she had been trying to get ahold of me because I was once again offered the James Bond deal. Hope to see you soon.
Love, Dad.
Alexis went through the rest of the paperwork in the envelope and found the deed to loft had been transferred into her name and Kate's. He had put Kate on the deed after they were married and was unable to get her name removed. The rest was the paperwork about her trust fund and a first class ticket to London. Not knowing how long her father had been gone she had no time to loose. She knew the only way to get her father back was for Kate to go after him. She had no clue what was in Kate's envelope but she an idea and hopefully it was enough to make Kate see that if she didn't stop what she was doing she was going to lose everything forever. Alexis gathered up Kate's paperwork and rushed back to the precinct. Not even bothering with formalities she ran into Kate's office. Kate started to tell her that she needed to leave when Alexis cut her off and told her that this was all her fault and it needed to be fixed now, not later, now. Alexis told her stepmother that her dad was gone, that she arrived home to find him gone. He had left something for her, she had no idea what it was but her last hope was that it would change Kate's mind. Kate told her that it was not that easy. That she had left her father not because she no longer loved him but because she needed to protect him and her from whoever Locksat was. Alexis understood, but that the two of them know that her dad and Kate's relationship has always been full of misunderstandings and now the worst misunderstanding of all had happened. Alexis handed Kate her envelope and told her to open it. She stood there and watched Kate open it only to have to rush forward and catch Kate as her legs gave out under her, saying as she fell, it's divorce papers. That this was not what she wanted. In it as well, was documents saying other than the loft which she now shared with Alexis, that he had left her everything stating from the lawyer, it was worth nothing to him anymore.
Alexis asked Kate if she was willing to let him go forever or was she was going to stand and fight for her life. Kate told her she was that was what she had been trying to do for months, but had come no closer to finding out who Locksat was and she had been getting closer with Burke every day to going home to her family, that she had been planning on going home tonight after the whole incident with Demming. That she knew from the look in Castle's eyes that the only way she was going to fix this was to go home where she belonged. Alexis smiled and said I hoped you were going to say that and she said here, he left this for me, but you need it more than I do. It's his address in London, and a first class plane ticket. I don't even care if you stay in London with him. Please go bring back the man we both love.
With those parting words, Kate hugged Alexis, grabbed her bag and ran. Kate got to the airport in record time. Kate never made it on the flight to London leaving in 30 minutes because when she got to the gate, there was Castle sitting and staring out the window looking so lost. It was all a blur after that, the only thing Kate knew next was that she woke up the next morning with her body entangled in her husbands who was fast asleep. In that moment, Kate swore no matter what happened, this was where she belonged and even though this fight was not over. They would be able to get through it together. Like always.