Genre: Crime, Drama, Romance, Family, Humor

Rating: M for violence, language and sexual situations

Disclaimer: I do not own the characters featured on the show Castle, they belong to the creator of the show, ABC, and the others who do own them.

A/N #1: Loved getting the reviews that I did for the last chapter, so going to go ahead and say thanks for them all. pcol22 (As always, so happy to see you liked the last chapter again. Was really glad seeing that you liked their family moment as you put it, I was wondering what readers would think of it. And was great to see you catching that Julia's getting closer to Castle enough to want him to come with Beckett to walk her to school, thought you might notice that. And thought it was interesting your comment about Amy, you'll see how everything'll go of course as I keep posting chapters, lol. And very happy seeing you want to read more, always love to read that in reviews!), vetgirlmx (Was so glad that you liked the beginning, with Castle and Julia playing. I really tried to write it like that, so loved seeing I managed to accomplish it! And I was really happy to see you mentioning Julia telling Beckett to thank Castle the right way, lol. And yeah, your reasoning is right, she wants them to be a normal family, but I did love seeing you thought it was sweet and cute too! And I had to laugh that you liked the ninja line that much; also glad you did too; I don't remember now if I made that up or got that from somewhere, but you're welcome to use it! And loved reading your reactions to the case so far and to see that you're still speculating, always good to see as a writer! Now though, you'll be able to see what'll happen next!), life's a mystery (Yet again, was so happy to see you too liked the family scenes at the beginning of the last chapter. And also that you thought I wrote it well! And your comment about the chapter made me smile, since it made you want to read more. And here's the update for you to read!) and sammysgirl78 (Have to say once more that I am again really happy to see you too liked the family moment at the beginning of the last chapter, and other moments since you used the plural, lol. And yeah, parents' beds seem to be best for kids to use to play 'cause they're big enough for the kids' imagination. I was so happy to see you mentioning the discussion between Castle and Beckett before Julia woke up, was wondering if anyone was going to notice that. But yeah, I figure with how different their lives are from before Julia came into their lives, had to have them actually say they're happy with the surprise of having her now, so glad you liked that. Another thing I'm glad you mentioned is Castle brushing and then braiding Julia's hair, thought it more than likely he would have done that with Alexis, so had to have him do that for Julia too, plus, I did want it to be sweet and I managed it! Also glad you too liked that Julia was upset with Castle not going with her and Beckett to her school but then taking her on his own later, as a said, a way to show that she's getting closer to him! Interesting idea for Julia not wanting to go to school, I actually hadn't thought of it, just remembering how I was not wanting to go to school, lol, but you make a good point. And you'll see what'll happen with the case now. So happy you want to read more too!). So great to see the reviews I got, thank you for them again, loved reading them. I appreciated the time taken to send me them, what was said in them as well, lol and of course am so grateful for them!

A/N #2: The title of this chapter is a lyric from the song Beware My Love by Paul McCartney, from the Wings album Wings at the Speed of Sound.

Tell You To Beware

The stage was dark, except for a solitary spotlight on the dancer, spinning before doing a pirouette and landing en pointe as a male dancer joined her in the light.

"I don't see Julia doing that."

"I know. Excuse me, I am Detective Beckett with the NYPD, I need to ask that you stop this dress rehearsal."

"Excuse me," a man said, standing up in the front row. "We're running tonight and-"

"Are you the director?" Beckett asked when she and Castle were closer to the man. When he nodded she showed him her badge as the theater lights came back on and said, "And I'm investigating a homicide. I need to speak with your lead dancer."

"Amy?" the director asked.

"What is it?" Amy said, going to the edge of the stage.

"Is there somewhere we can talk to you in private?" Beckett asked.

"Sure, I'm sorry Joey," Amy said to the director. "They're investigating my mother's… my mother."

"Oh, why didn't you say in the first place," the director said, instantly becoming solicitous. "Take them to your dressing room Amy."

"This way please," the dancer said, motioning backstage. When Castle and Beckett were following her she went back to a small room where there was a small couch across from the vanity. "Sit, please. Did you find my father?" she asked as she closed the door.

"We did," Beckett said simply.

"Oh, thank goodness," Amy said, touching her cheek. "Did he confess to killing my mother?"

"There's a funny thing about that," Castle said. "Well, it's not so much funny as a little strange. He can't speak."

"Can't speak? What are you talking about? I told you he called me-" Amy said.

"Do you recognize this man?" Beckett said, holding out the picture of Costa that had been taken at the Precinct for identification purposes.

"This is… no, I don't, who is it?" Amy asked.

"Your father," Beckett then said simply.

"That's not him," Amy said. "I don't know what he told you, but that's not him."

"Oh no, that's Philippe Costa, however, he's deaf and mute. And he's not your mother's killer," Castle said.

"He's not?" Amy asked in shock.

"His alibis for your mother's murder, the murder of Lorenzo Martine and your attack all checked out," Beckett replied; since Esposito had called them before they'd gone into the theater with that information. "So who was it that was getting money from you?"

"I don't know, he said he was my father, that he knew things…" Amy said. "I can describe him, if you want me to."

"Then you'll need to come with us down to the station," Beckett said, standing up. "They'll have to continue the rehearsal without you."

"So we talked to Longueville," Ryan said as he was with Beckett and Castle at her desk. "And she didn't know about the inheritance, neither did the other friends of course. I contacted Amber Holsten, but she couldn't think of any past exes or friends that would have known about it to threaten her sister."

"We need to ask her something that's been bothering me," Castle said, looking at Beckett. "Where it was this guy contacted her the first time."

"You make a good point, hopefully somewhere with security cameras," Beckett said as she saw Esposito coming out of the conference room with the sketch artist's notepad. "That's him?" she asked.

"That's him, he's about forty to fifty, five nine to six feet and his hair is black. She says she's only had a picture of him from about twenty-five years ago, so she took this guy at his word that he was her father since he looked similar to him," Esposito replied as Beckett took the sketch.

Handing it off to Ryan, she went over to the room and said, "Ms. Holsten, I'm wondering where was it this man first contacted you before he started the mail drops for cash?"

"In my apartment, oh, they have security cameras in the halls; after a fire was set about ten years ago; and he should be there. It was… on a Friday, I remember because I had finished a class that day and was about to go out to a bar; my usual routine that day," Amy replied as she put on her coat.

"Thank you for your time, I'd ask you not to leave the city until we find who the killer is," Beckett said.

"Am I a suspect?" Amy asked, looking slightly taken aback.

"No, but the killer might be after you and your sister, you never know," Castle said, standing behind Beckett.

"Of course, I have the show tonight, so, I won't be going anywhere," Amy said, smiling briefly before she left with the officer Beckett had assigned to escort her back to the theater.

Watching the young woman go, Beckett wasn't too surprised she didn't feel much sympathy for her, and she quickly turned to the boys who were at the board but were watching the dancer leave. "Guys," she said to them. "I need you to get on the phone to her building, and get security footage from the twenty eighth of last month outside her apartment."

"Think he'd really make that bad of a mistake?" Castle asked.

"There's a part of me that's really hoping he did," Beckett said. "I need to go home to her to tell her it's over."

"Yeah," Castle said, knowing what she meant. "But it doesn't feel right, does it?" he asked as they went to the break room.

"Not entirely. I'm thinking about bringing in the friends of Martine, to look at the sketch and see if we can get an ID," Beckett mused as she leaned against the counter next to Castle. "But it's…"

"Not coming together," he finished for her. "I agree, but maybe he's a not fully intelligent murderous psychopath."

"To murder a baby, I'll agree with that description," Beckett said. "Though, why would he bother with the baby?"

"To throw us off the trail of the money I would hazard a guess," Castle said, handing her a cup of espresso. "But, if I'm writing the story and this guy's a psychopath, then the money and the pregnancy came together in his motive."

"Beckett," Esposito said, coming to the doorway. "We've got the security footage."

"Great, I want you to get Costa released and Ryan," Beckett called to the detective as she left the room. "Go ahead and look through the Post Office footage again now we have a different suspect."

"You want to take the footage from the building," Caste said as they went into the room while Esposito went to his desk.

"I'd like to check for myself," Beckett said, going back to the doorway as an aide was coming over to them. "Thank you Leticia. So we have a sketch," she said, holding up the copy she'd been handed. "Let's take a look at Amy Holsten's Friday."

Sitting with her, Castle looked on as she fast forwarded until a person came into view. He looked carefully at everyone, but no one was stopping at the apartment door in the middle of the screen; Amy's; and none of them looked like the sketch. "Luckily it's only one day," he commented as they finally reached the afternoon a little while later; having stopped to watch a woman speak with Amy who'd stood in her doorway before going into the apartment across the hall.

"How do you know her memory was correct?" Beckett asked, looking up at the screen.

"Why do you have to be so pessimistic about this?" Castle groaned slightly. He glanced at the TV and then straightened up in his chair at the same time she did. Looking at the sketch and then the screen he said, "That's him."

"That is," Beckett replied, pausing and zooming in on the man's face. The large beard matched the one in the sketch that Amy had described and so did the arch of his eyebrows which were easily seen. Playing the footage again, they watched as the man walked into the apartment after Amy had opened the door and then stepped back in.

"He waited until he was inside to threaten her," Castle said as Beckett was writing down the time the man had gone inside. "See how easily he got in?"

"I saw," she said simply as she played the footage again. She fast forwarded it until the man left, and paused as he walked out. "He was only in there for fifteen minutes," she said as she looked at the two times.

"She must have acquiesced in a hurry," Castle said as on the screen Beckett played the footage out and they could see the man getting on an elevator.

"Guys," Esposito said, at the door then.

"Costa's out?" Beckett asked, getting her phone out of her pocket.

"Not really, it's Costa, he's downstairs in the lobby, refusing to leave until he can speak with you," Esposito said. "Here," he said as he held out a notepad and paper to them.

"Actually, I need you to take care of him," Beckett replied, dialing out the building's number but not hitting the call icon. "If he asks about his daughters, just tell him we'll get in touch with him as soon as the case is finished and he needs to leave a way for us to contact him." Once Esposito had left with a nod at her instruction, she finally made the call as they watched their suspect go to the elevator for a second time.

Castle paused and tried to zoom in on the numbers at the top of the screen to see where the man had gone to, but a number of floors; Amy being on the twelfth of a twenty story building; lit up and he knew there was no way to tell where he'd stopped that way. He watched Beckett then, hoping the building had footage of the man getting off the elevator at some other floor.

"Thank you, goodbye," she was saying before she hung up. "Okay, they're looking at the sketch now, and will have someone look at the other footage from the others floors to figure out where he went."

"So we wait?" Castle asked.

"We do, but I want to check in with Ryan and we should go over the case," Beckett said. "One more time to make sure we're not missing anything."

"After you," Castle said as she stood and he followed her out, glancing back at the elevator doors that were on the TV screen.

"Finished up with the footage from the Post Offices," Ryan said, walking up to Castle and Beckett who were at the murder board. "But never saw the guy at all, not even in a disguise or anything."

"He probably did," Castle commented. "It was just good enough to fool you into not seeing him."

"Did the warrant come in for Holsten's financial records?" Beckett asked, turning then to look at him.

"No, not enough to issue it," Ryan said apologetically. "I tried to explain Castle's theory but they told me I was out of my mind and the judge would never sign for that."

"Told you," Beckett said with a sigh. "Alright, so we've looked at the money, we've looked at the baby; babies; and we've got possible motive or motives. But nothing that's coming together enough to build a case a jury would believe. If we even had a suspect of course. But something I thought was what about a simple stalker?"

"Stalker?" Castle asked in surprise.

"I know, not as exciting as what you've come up with, but it might explain why Martine was killed as well," Beckett said.

"That's not a bad idea," Esposito said. "There's a report that the vic, the first vic, filed about seven years ago. We didn't find it because someone put it under the name Costa when it occurred," he said, handing a copy of it to Beckett.

"She accused a Patricia McInnes of sexual harassment," she said as she was reading. "And the woman was eventually charged with stalking, but everything was thrown out because she was deemed insane. We…" Beckett started to say before trailing off. "This is her?"

"Yeah, have you seen her?" Esposito said as she showed the picture to Castle.

"Definitely," he replied as Beckett strode back to the TV. They watched as she pulled up the security footage of the hallway they'd been watching earlier, and paused on the woman they'd seen talking to Amy Holsten.

"That's her," Esposito said as Beckett zoomed into the woman's face and it was a match to the picture of the woman.

"Let's go," Beckett said shortly as she turned off the TV and they hurried out to grab their coats on the way to the elevator.

"Detective Beckett?" a man in a suit and red tie asked as she and the others walked inside the lobby of Amy Holsten's building.

"Yes, were you able to find out who the man was?" Beckett asked.

"We think he might be Ralph Joyce, in 19L, but he's clean shaven," the man replied.

"Do you know this woman?" Ryan asked, handing him the picture of Patricia McInnes he was holding.

"Oh yes, she's the woman living across the hall from the apartment you were looking into," the man said. "Ms. McInnes."

"Alright," Beckett said, turning to Ryan and Esposito. "I want you two to get McInnes, Castle and I will get Joyce."

"Sure you want to head up with no backup?" Esposito asked.

"These two might be working together for all we know," Beckett said simply. "I want them at the station as soon as possible."

"Want to give me your backup at all?" Castle asked when they were in the elevator.

"I don't think it's necessary," Beckett replied simply. They stopped at the floor where Amy Holsten's apartment was, and Ryan and Esposito walked off. She looked up at the numbers and said, "We're just bringing him in."

"Doesn't mean he wouldn't get violent," Castle said before they stopped at the nineteenth floor. He followed her around the corner and then said, "You don't think it's weird he's clean shaven?"

"A disguise," Beckett said, but without much conviction as she had to admit he was right, it was strange. They reached the door and she knocked on it calling, "Mr. Joyce?"

"Yeah, can I help you?" a middle aged man said, opening the door a moment later. His eyes widened at seeing Beckett's badge and asked, "What's wrong?"

"We're investigating a homicide," she replied. "And we'd like to ask you some questions; at our Precinct."

"Mr. Joyce," Beckett said as she walked into interrogation a short time later. "I see you have some arrests on your record, mostly domestic abuse."

"Yeah, you said someone was murdered though," Joyce said as she sat across from him. "And those arrests were when I was much younger."

"True, but that doesn't mean you've stopped," Beckett said simply, going through her folder. "Do you know this woman?"

"No," Joyce said very slowly. "She looks a little familiar though…"

"What about her?" Beckett asked, showing him a picture of Amy Holsten.

"Oh, yeah, Amy, she's a few floors down from me," Joyce said with a nod. "Is she okay?"

Beckett paused, slightly taken aback by the sincere concern in the man's voice. She recovered quickly though and said, "The woman in the first picture is her mother, she's our victim."

"That's horrible," Joyce said. "But… you don't think I killed her do you?"

"Have you ever heard of a drug called succinylcholine?" Beckett replied with a question.

"Uh… not really, listen, I didn't kill this woman, I had no idea who she was," Joyce said. "Amy never really talked about her when we were together." He turned his head and said derisively, "The short time we were together."

"You had a relationship with her?" Beckett asked.

"Yeah, it was… pretty much friends with benefits, we met in the laundry room and it went from there," Joyce said. "She noticed that my clothes were covered with paint and talked about she had always wanted to be a painter herself but her mother had never let her, made her dance instead."

"When did you stop seeing each other?" Beckett asked.

"Three weeks ago," Joyce replied.

"Is this you?" Beckett said as she handed him a screenshot of the security camera footage.

"Yeah, it is, that was really bizarre, she wanted me to dress like a homeless guy," Joyce said. "I thought she was a little off, but thought whatever she was… it was worth it," he hesitated before finishing. "But as soon as I got into the apartment she made me take everything off until I was leaving and had to put everything back on. And then as I was going to the door she suddenly ended everything. I tried to talk to her, but she just threw me out of her place and I haven't seen her since."

"Where were you between twelve and two three nights ago?" Beckett asked, seeing their chance slipping away; hoping Esposito and Ryan were having more luck with McInnes.

"Home, painting, there are security cameras on my floor too," Joyce said.

Beckett asked about the next two times, but barely listened to the man give the same alibis. "Alright, I'll need to keep you here until we can check those out. By the way," she said. "Do you know who these men are?" showing him pictures of Costa and Martine.

"No," Joyce said after studying the photographs closely.

Standing, Beckett left the room with Castle coming out of observation behind her saying, "Espo and Ryan are still in there, we need to check on his alibi ourselves."

"And take another look at the case?" Castle asked, though he didn't sound too sure of himself. When his fiancée stopped and looked at him he said, "I have an idea."

"A theory? Please share with the class Mr. Castle," Beckett replied.

Shaking his head, Castle replied with, "It needs some fine tuning."

"Evidence," Beckett said simply. When he nodded once she turned back to her desk and sat down, calling the building where Joyce, McInnes and Amy lived.

"So McInnes is a dead end," Esposito said as he and Ryan walked over to Castle and Beckett from their desks.

"Her alibis checked out?" Castle asked, turning from the murder board.

"Oh, you could say that," Ryan said. "She was with her lovers, every single time we have for the murders and assault."

"Was she Holsten's lover?" Beckett then asked.

"Until about three weeks ago," Esposito answered. "Don't ask why she went after the mother and then slept with the daughter, she just said she wanted to."

"The same as Joyce," Castle said. "Not in the least suspicious," he said sarcastically.

"Not all," Beckett replied, though she was looking at the board unseeingly. "Alright," she shook herself. "Let them go Esposito, we confirmed the three alibis from Joyce."

"Anything from looking over this for a second time?" Ryan asked once their partner had left.

"Oh, nothing much, but we decided we're both thinking towards the same direction," Beckett replied.

"We're heading to Amy Holsten's, we need to speak with her," Castle said. "For a second time today."

"Which I'm overjoyed about," Beckett said, looking at their timeline again.

"Do you want us with you?" Ryan asked.

"Yes," Beckett said, seeing Esposito was already returning.

"Thanks for filling out most of the paperwork, did we have to keep talking to her though?" the detective asked when he was close.

"I'm afraid so, but we'd gotten the footage of the hallway the other two time periods while we were getting them in Joyce's hallway," Beckett said, going to her desk and switching to her coat. "We're heading to Amy Holsten's, all this is looking very badly for her."

The four traveled separately to the building yet again once they were out of the Precinct. In the lobby, Beckett directed Esposito and Ryan to speak to the concierge the building had, to see if there was a sign-in sheet for guests, wanting to get a look at past guests to Amy's apartment before they resorted to the security footage of her hallway once more.

"We're not bringing her down to the station?" Castle asked on the elevator up.

"It wouldn't work," Beckett said. "I want to lull her into a sense of security before I start tearing her story apart."

"Great," Castle said. When she looked at him at his enthusiasm, he quickly said, "I love seeing you on the attack."

Not replying to that, Beckett headed out into the hall as they'd reached the twelfth floor. When they neared 12R, she saw that the door was opened slightly, and she reached under her coat, keeping her hand near her gun. She looked back at Castle and saw that he'd pressed against the wall as she'd done. Nodding to him, she turned and got closer to the door, pushing it in before pulling out her weapon. Aiming it in front of her, she stepped inside, hearing a distant creak of the hardwood floor ahead of her. Going to the side of the doorway to the bedroom, she looked in and saw it was empty. Hoping that it was a false alarm, she stepped inside fully and put her finger on the trigger, seeing Amy being held by a man, a knife pressed against her throat as she struggled against her attacker.