She begins laughing hysterically. He puts down the knife, and just stares at her. Eventually she stops laughing, and composes herself.
"Are you done?" He queries.
"That is a completely laughable theory."
"Why?"
"Because it is. Don't you think that I would mention having a daughter?"
"I don't know," he shrugs, "Javier never mentioned it."
"You don't share a bed with Javier."
"That isn't the point. The point is that you keep a lot of things from me."
"Do you really think that I am that cold? Rick do you really think that I am capable of hiding the fact that I have a daughter from you? For four years?"
"I don't know what you're capable of. I feel like I don't even know you right now."
"I am not her mother."
"She even looks like you," he points out.
"Richard Castle, listen to me, I am not Sydney's mother."
"Then who is. Why did you have ice cream with her, today?"
"It's complicated."
"Kate, please just tell me the truth."
"I had ice cream with her, because she asked me to."
"Why?"
"Because when she needs to talk to someone, and she can't talk to Javi, she calls me."
"Why you?"
"You were right."
"You are her mother?"
"I don't share everything with you. There are some things that I don't tell you."
"Like the fact that you have a daughter?" He responds, still outraged.
She shakes her head, "No."
"So what aren't you telling me?"
"Sydney calls me, because I am her aunt."
"He aunt? You mean she calls you aunt Kate? Are you like her godmother, or something?"
"I am her godmother, but that isn't what I am trying to tell you."
"What are you trying to tell me?"
"I am her aunt."
"That's not possible. Last time I checked Javier is not your brother."
"No!"
"And you're an only child."
"Sort of."
"What do you mean, sort of?"
"I am not an only child."
"Since when?" He cocks his eyebrow.
"Since the day that I was born."
"What?!"
"I have a sister."
"No, you don't," he argues.
"Yes, I do."
"Like a half sister?"
"No," she shakes her head.
"I don't understand. If you have a sister why haven't you ever mentioned her before?"
"We had a falling out."
"Your father has never mentioned her, either."
"They had a falling out, too."
"What happened?"
"She came home for my mother's funeral, and spent the day before the funeral drinking. She never showed up to the funeral. We found her passed out in her hotel room. There was a heated discussion, and we parted ways after that."
"You're being serious right now?"
"Yes."
"What's her name?"
"Kelly."
"Kelly?" He cocks an eyebrow.
She nods in confirmation, "That's what I said."
"How much older than you is she?"
"Fifteen months."
"So she's the black sheep of the family?"
"She always has been. She joined the army when she was nineteen. She missed my mother's funeral. She ended up pregnant out of wedlock. She eloped when she returned stateside. My father has rarely approved of anything that she has done."
"Does he even speak to her?"
"No."
"What about Sydney?"
"He sees her, and spends time with her."
"He never talks about her."
"Then he would have to talk about Kelly, and he refuses to do that."
"Was your sister married to Javier?"
She nods, "Yeah. He really tried to make their marriage work, but it is difficult to make things work when your spouse is halfway around the world, and you're at home alone, with a baby."
"I can't believe this," he admits.
"I know."
"So Javier, and your sister were married?"
"Yes."
"And they have a daughter together?"
"Yes."
"And you have a sister?"
"Yes."
"Her name is Kelly?"
"Lieutenant Colonel Kelly Beckett."