A/N: This is NOT a crossover fiction. If it was, I would have obviously labeled it as so. But thanks for that charming review, anyways.

Kate's jaw dropped and she couldn't get a word out. Rick, however, covered his mouth in shock and almost squealed.

"A real vampire?!" Rick asked, sounding like he'd just won the lottery. Kate rolled her eyes in annoyance, but she felt almost skeptical now.

"Not exactly. Genetic experiment, I'm guessing."

"That would explain why there's no record of her," Kate said finally, glad for a slightly more logical explanation. "She wasn't human, she was a genetic experiment."

Lanie nodded, dropping the girl's lip to cover the fangs again. Rick's face fell a bit, but the excitement didn't disappear. This was the coolest case ever.

"So she was an escaped experiment?" Kate asked. Lanie nodded again.

"Maybe someone killed her because they found out and didn't want... whatevers roaming the city," Rick said. Kate almost questioned his rational response but thought better of it, instead nodding.

"That's possible. Thanks, Lanie," she said as she turned and headed out the door. Rick shot Lanie an "oh my god!" look before following Kate out.

Lanie looked at them leave and shook her head once they were gone. "I swear, if they didn't drive each other crazy, they'd drive each other crazy," she noted as she covered Amber's head again.

"We're got nothing," Esposito said with a sigh as he and Ryan approached Beckett and Castle, who were staring at the murder board again. "No one's seen him before tonight. Guy's like a ghost. No one has an idea who he is."

"What about Amber, have any of them seen Amber before tonight?"

He shook his head. "Nada."

Kate turned to look at Rick. "Whoever was hunting her down knew what she was. They probably hunted her down because of that."

"Or maybe it's just a coincidence," Rick added. Kate shook her head.

"Can't be. Someone gets hunted down and murdered and they turn out to be a genetic experiment?" Kate shook her head, knowing that the killer knew and that was the reason she was killed. But who was the killer?

"Alexis, do you know if anyone wanted her? Mysterious phone calls, stalkers, people following her when you two were out, anything like that?"

Alexis, who was sitting on Kate's chair behind them, shook her head for a moment before nodding a bit. "Actually, yeah. She kept getting these mysterious phone calls. And she'd always look pale after them."

"When was the last time she got a call like that?" Rick asked his daughter.

"Two hours before we went out. She almost cancelled, but I convinced her otherwise…" her voice fell and she bit her lip back, turning her attention back to the floor.

Kate turned back to Ryan and Esposito. "Run her phone records. Find out what phone the calls came from, and who owns the phone. Maybe we can find the killer."

The boys nodded and turned away. Kate turned back to the murder board, letting out a sigh. It was getting late; she and Rick had spent all day coming up with new theories, none of which helped even in the slightest.

"I think it's about time we called it a night," Rick said, meeting her eyes, clearly pleading her to come home with him. She held back the urge to roll her eyes and nodded, hopping off the desk and grabbing her coat. "Goodnight guys," she called to the boys behind her as she left with Rick and Alexis.

Once they got home, Alexis headed for bed right away, leaving Rick and Kate alone. Kate threw her coat down and turned to Rick.

"So do you believe now?" He asked her, clearly talking about the case. She couldn't stop herself from rolling her eyes, but she smiled despite herself.

"There's a logical explanation, Castle. There's nothing supernatural about this," she said matter-of-factly as she made her way more into the house, Rick following close behind.

"But it's close enough. And who knows, maybe they are real vampires and monsters out there," he insisted.

"Or maybe not," she laughed, turning towards him and tugging him close. Before he could speak back, she kissed him, silencing him as his attention turned from the case to the kiss. He was still adjusting to the fact that they were actually together now, that he could do this whenever he wanted. Obviously, not at work, for they were trying to keep it a secret. It was hard to keep from taking her hand or giving her a quick kiss at work, but that's why they always came home together. So they could do this in complete freedom.

It was hard to believe that Kate was actually his, after being in love with her for so long he was almost sure she didn't feel the same way. But that night she'd shown up on his doorstep, announcing that she wanted him, was a night that changed everything; and probably for the better.

They finally broke the kiss, smiling at each other for a moment as their hands wrapped together at their sides. Rick felt the familiar feeling of butterflies as he looked into her eyes, and she tugged at his hand as she led him towards the bedroom.

"You seem to be in a good mood this morning."

Kate Beckett blinked, looking up for the source of the voice. She'd been zoned out with a stupid grin on her face, lost in the thoughts of last night. They hadn't done anything like that since the murder, and it was blissful as always. She cleared her throat, pulling herself back to reality. Esposito was smirking; he'd seen the same look on Rick Castle's face as he loaded the coffee machine only a few minutes ago. He knew what had happened, but he kept it quiet, enjoying her embarrassed face a little bit too much.

"Did you get a hit on the call?" Kate asked in her best cop voice, attempting to wipe all the embarrassment off her face.

"Actually, yes. It belongs to a miss Bethany Hillbaker."

Beckett raised her eyebrows. "They must be connected in some way."

"I have good news, though. We have a match on the cell phone." Esposito handed her a sheet of paper with a photo of a bright blue phone. Kate looked in confusion for a moment before it dawned on her.

"This is the same phone they found smashed at the end of the alley," she said in shock. Esposito nodded.

"But the killer was a man," Kate said in confusion.

"What are you guys talking about?" Castle asked as he entered the room and set down a coffee for Kate. She didn't meet his eyes as she felt the blush returning, and Esposito's smirk grew.

"Ooh, I like that phone," Rick said as he took the sheet from Kate's hands, ignoring her annoyed look at him. "Bethany has this."

Kate's head snapped up. "You know her?!"

"Yeah," Rick said. "She was at one of my book signings. It was weird, she asked a lot of questions about Alexis and her friends."

"When was this?" Esposito asked.

"A few months ago, why?"

"Because Bethany is our second witness," Kate said, removing the sketch from the board and handing it to Castle. "Is that her?"

"No, she looked different. Her hair was ginger and she had a different-looking face…"

"She must have changed it," Kate said, putting the photo back. "So this Bethany girl is our second witness. Get uniforms to bring her in," Kate told Esposito, grateful for this break.

"One problem," Esposito began with a regretful expression. "She doesn't exist, either."

A/N: Leave reviews! Thanks for reading.