"It is also important to realize that they are not, strictly speaking, universes either, but it is easiest if you don't try to realize that until a little later, after you've realized that everything you've realized up to that moment is not true." – Mostly Harmless, by Douglas Adams

Kate Beckett sat cross-legged on the pavement at the intersection of East 12th Street and Avenue C, eyes shut, phone in her hand. If she hadn't just seen fairly convincing evidence that her mother was still alive, she might be concerned about the fact that sitting down on a New York sidewalk wasn't the safest or sanest thing to do. As it was, she was perfectly content to let the foot traffic pass her while she attempted to hang on to what still made a smidgen of sense- the insides of her eyelids.

Pieces were beginning to fall into place. A picture was beginning to form. The mere fact that she could see a picture beginning to form worried her and she was pretty sure that she liked it better when she was confused.

Her mother was alive. Ergo, her mother's murder had never happened, ergo, she had never become a cop. Also, if her mother's murder had never happened then the events leading up to her mother's murder had also never happened, which explained the living breathing not-a-captain Captain sitting at her desk.

Rationally, she couldn't just sit here on this concrete for the rest of her life. She had a job as an actress (apparently) and she'd have to keep that. She'd grow hungry, it would rain, she'd grow uncomfortable under the stares of passing pedestrians. Still, a part of her (a large part of her) didn't want to leave. This world, or parallel universe or acid trip or whatever it was, was too hectic and full of twists and turns and changes. If she just sat here on the sidewalk she could avoid all that.

Her cell phone rang again, and she opened her eyes to glance at the screen. It was Mona. With a deep breath, Kate made her decision, turned off her phone, stood up, and hailed a taxi.

Beckett stood in front of the door to Richard Castle's apartment, deliberating. Going in and watching Castle not recognize her could mess with her head more than anything else. On the other hand, seeing Castle at all might make her feel better. Gathering her courage, she knocked on the door and watched as it opened moments later.

"Hey!" said Castle, seeing her as he opened the door. "I thought you were in LA."

"You… you know who I am," she said, startled but happy.

"Of course I do, Maia Sound," he said jokingly, inviting her into the loft. "You here to get some more shadowing in with me and Amy?" Alright, so she didn't know who this Amy was, or what the significance of "Maia Sound" was, but so far so good. He recognized her.

"Actually, I just… I'm having a weird day. And I was in New York, and I didn't know who else to come talk to…" He closed the door behind her, turning to look at her with a concerned expression.

"Do you want something to drink?" he asked, leading her to the couch. The furniture here was just the way she remembered it. More reassurances. Add that to the fact that not only did he know who she was, but he seemed to care about her wellbeing, and her frustrating morning was beginning to turn into a slightly better day.

"Water." She hadn't until now realized how thirsty she really was. "Lots of water."

"Are you in some kind of trouble?" asked Castle while he poured her water. The many different connotations and definitions for "trouble" rushed into her mind- pregnant trouble, drug trouble, money trouble. She wasn't quite sure how to describe her situation.

"The butterfly effect is screwing with my brain." There were several books lying on the coffee table in front of her, and one of them mentioned something about Maia Sound on the back. While Castle filled his own glass of ginger ale, Kate picked up that book and read the summary on the back.

Singer Maia Sound had it all- best friends, money, and excellent talent… until a competitor band, The Misfits, burned down her father's foster home and ran her out of the family fortune. Now Maia must gather up her friends for a concert to raise money for the orphans and bring The Misfits to justice, but not if the new CEO of her father's company has anything to say about it.

It was difficult to avoid rolling her eyes. "Let me guess," she muttered to herself, "it's called Sound Wave." She flipped the book over to see that the title was, in fact, Sound Wave. "Of course."

"Here's your water," he said, handing the glass to her as he sat down in the arm chair across from her with his ginger ale. "Now… what's wrong?"

Kate sighed. "Have you ever just woken up one morning and nothing is the way you always remembered it?"

"You mean like in Hangover?" said Castle. Great, she thought to herself. She had a completely different career and the series written based on her had vanished from existence, but Hangover was still around.

"No," she sighed, sipping her water to avoid talking. She wasn't quite sure how to proceed. "You're into all that sci-fi conspiracy stuff, right?" She was trying to draw comparisons between this guy and the Castle that she knew and… that she knew.

"Always," he said. She felt a twinge in her chest.

"Well," she started, deciding to just get it done with, "the thing is… it's… here's what the thing is. I'm not really an actress."

"Is that like 'I'm not really a waitress'?" he asked with a cocky grin. She set her mouth in a line, worried that he wouldn't take her seriously.

"No," she said, keeping her face as straight as was humanly possible. "I'm really not an actress. At least, last night I wasn't. Last night I was an NYPD detective, and when I woke up everything was different and I wasn't a detective and my mom was alive and the people who are supposed to know me don't-"

"Okay, okay, I believe you," said Castle, crossing the distance between them swiftly and moving to sit beside her on the couch. He put an arm around her like it was the simplest thing in the world, trying to comfort her.

"Just like that?" said Kate, surprised. She was even more surprised that the rims beneath her eyes were damp, and her throat was catching. "Ryan and Esposito didn't believe me."

"I've got a really open mind," he shrugged.

"I know." She exhaled and wiped her eyes, then started disentangling herself from Castle. "You don't really believe me, do you?"

"Believe is such a vague word-"

"It's okay," she said. "I don't believe me either. I probably have some sort of brain tumor. You might not even be real." She poked him. He was real.

"It would make a cool story," he said. "If that were the sort of thing I wrote."

"What kinds of things do you write?" she asked. That Sound Wave book had not at all seemed like the kind of thing Castle would write.

"Celebrity stuff," he said. "People living the good life until something bad happens and then their life… stops being the good life." Again, it was difficult to not roll her eyes. "I follow a lot of heiresses, actors… you know this, I asked to follow you once."

"Of course you did." Some things never changed. "Look, Rick, I'm sorry I told you all this, maybe I'm just having a weird day."

"Weird days are good, Kate," he said. "They keep life interesting."

"I think I liked my boring catching-murderers life," she sighed, downing the rest of her water. "Thanks for the talk. And the water."

"Looking forward to seeing Sound Wave on the big screen," said Castle as she stood up. "Oh, and if you run into Amy, would you not mention New Year's? She and I are kind of… almost-there. If you know what I mean." There was that mysterious Amy again. Kate refused to believe that the sudden jerk in her stomach was jealousy. If anything, the water he'd given her was past its expiration date. Yeah, that was it.

"What about New Year's?" she asked. If she was going to avoid telling someone she didn't know something she didn't know, she may as well know what the thing she wasn't supposed to say was.

"The naked part," laughed Castle. She nodded, chewing on her lip to avoid freaking out.

"Right," she said when she had recovered herself. "I'll see you around, Castle."

"See you." She took a deep breath and headed out the door into the upside-down inside-out world.

A/N: Shout-out next chapter if anyone can guess the 80's cartoon from which Sound Wave borrows a lot.