Disclaimer: I claim nothing except the plot. I just had a plot bunny that either needed shot or written. I'd say I chose the less violent one, but you'll have to read to find out.

This is a completed work and will be updated on a regular, or at least semi-regular basis. Please, enjoy and review.

Kate Beckett sipped her steaming coffee, waiting for her crew to come in. She knew she was in early, so early that she ran into the graveyard shift. As they started thinning out, though, she started going through her case files for the day and mentally making odds for who would be in first.

Esposito would be the first one in, followed by a rushed Ryan. Castle wasn't due to be in today unless they got a call. She enjoyed slower days like this. Paperwork took on a mind of its own if it was left undone for too long, and she hated to do paperwork.

She nodded at Capt. Montgomery as he walked through to his office. He returned the nod and flashed her a pleasant smile. Those smiles were few and far between, and Kate knew that it should be a slow day.

Fifteen minutes later, she glanced up as someone walked in. Disappointment stung her as she realized that she'd lost her personal bet. Rick Castle was walking through the office.

"You're in early," she said drily. "What are you doing here?"

He grinned, but she noticed immediately it fell short of his normal charm. "I thought you'd just be thrilled to know that I'm going to be gone for several days."

"Oh?"

Slipping into his chair, he leaned across her desk and stole a piece of candy from her candy dish. "I am accompanying my mother to her premier in Chicago. She's not only starring in this show, but she's also one of the producers."

"Really?" Kate said, skepticism heavy in her voice.

Castle grinned and shrugged carelessly. "All right. So I loaned her the money that she put in. It was a good risk. The part was written for her, and she plays it perfectly."

Kate sat back in her seat and crossed her arms. "I never took you for a shrewd businessman. Always thought you paid people to take care of your money."

"It's my mother," he said as though it explained everything.

And it did. She knew that Castle had a closer relationship with his mother than most men, and the fact that she lived with him didn't explain all of it. "When are you leaving?"

He shifted in his chair, and again Kate's instincts picked up on something in his manner. "I've got a couple things to do, but we have a flight later this afternoon. And then after the show I'm going to go ahead and take Alexis to L.A. to see her mother. It's been a while."

She cocked her head and gave him a hard look. "Castle, is everything okay?"

"What? Yeah." His cocky grin was back nearly at full strength. "And here I thought you'd throw a party 'cause I'm gone." Returning her stare, he added, "Are you actually concerned about me?"

Kate knew that she had lost. "Oh, please." She took the out he offered. "Go on. Have fun."

"Will you miss me?"

She fought back a blush at that. "Go. Now. Or I will shoot you."

That brought a hearty laugh. "Now I can go." Standing, Castle dipped into a respectable imitation of a gracious bow and kissed her hand. Laughing in the face of her glare, he nearly skipped out of the office.

His departure was followed by Esposito's arrival. "Was that Castle in here this early?"

"Yeah. He's going to Chicago with his family and wanted to tell us goodbye." She paused, debating whether or not to mention her misgivings. "When was the last time you talked to him?"

Esposito shrugged. "Yesterday, I guess." He eyed her warily. "Why?"

Kate shrugged off the question. "Nothing." She looked back at her pile of paperwork, but it had lost what little appeal it had. Opening up the top file, she began plowing through the reports.

She saw Ryan come in, late as she'd expected, but with all three of them working on files, the morning went quietly. So quietly, in fact, that when her phone rang she jumped violently.

"Beckett."

She saw Ryan and Esposito lift their heads in unison as they looked toward her.

"On our way." She hung up and stood, pulling on her jacket and checking her weapon in one smooth motion. Hesitating as she reached for her cell, she stopped when she remembered that Castle wouldn't be joining them. "Got a DB, guys. Let's go."

As they drove to the address, Becket noticed that the street was familiar, but it wasn't until she actually got out and saw the tape stretched that she realized where they were. "Figures."

Ryan looked toward her. "Excuse me?"

Beckett smiled tightly. "That's Castle's building just across the street there. He could've walked down in his pajamas."

"Oh, don't tempt him. He'll make you eat those words," Ryan laughed.

This grin was a little more genuine, but it faded quickly as she faced the crime scene. Slipping under the tape, she approached the body. The victim was an older man dressed in a dark blue suit. Beckett's instincts that had twitched that morning now rushed back with a vengeance. Her frown growing, she knelt by the body.

"What's wrong?"

She glanced at Lanie, who was already in place. "What?"

The M.E. stared at her. "You've got that look like something's up, and you've barely seen the body. So what's up?"

"I know this guy."

"You do? What's his name? I haven't found any identification on him."

Beckett shook her head. "No, I don't know his name, but I've seen him before. I know it."

"Yeah, you have," Ryan said as he walked up. "He's the doorman for Castle's building."

"Where is Castle? I thought he'd be here by now," Lanie said.

"Supposedly on his way out of town." Beckett stood and stared at the victim before turning to stare up toward Castle's penthouse. "Excuse me for a minute."

She strode purposefully across the street and into the lobby of the apartment building. As she walked, she remembered seeing the man present at the front of the building. He hadn't been there every time, but had been there enough to make an impact. Her trip up to Castle's apartment was too short for her to gather her thoughts completely, so she stood for a long moment outside his door.

Finally she knocked. She was startled to hear all of the locks being undone. In fact, she expected to see Alexis when the door opened, but instead she looked up into Castle's face.

"Beckett. What are you doing here?" he asked, startled.

She opened her mouth to speak before finding the words. "Um, can I come in?"

He blinked a couple times before shaking himself out of his hesitation. "Oh, uh, yeah. Come on in."

Beckett walked in, suddenly unsure of how to handle this. Most residents in the penthouse wouldn't even look at the doorman, let alone be friendly with him, but Castle seemed to write his own rules. "There was a murder across the street."

"Really?" In spite of himself, he dashed over to his front window and gazed down onto the street below. "Figures." He turned to face her. "You didn't just come up to tell me that, did you?"

There were days when she really hated his insight. "The victim was an older gentleman. He's been tentatively identified as the doorman for your building."

The color drained from Castle's face, and Beckett wasn't sure that he wasn't going to pass out. "Are you saying it was George?"

She nodded. "Castle, I recognized him."

He sank down onto an ottoman and stared off blankly. "I just saw him this morning on my way out. He, uh, he wasn't there when I got back, but I assumed he'd just gone home early."

"Why would he go home early?" Beckett asked, slipping into what Castle referred to as her 'cop mode'.

Running a shaky hand through his hair, Castle shook his head, still not meeting her eyes. "He had bad arthritis in his knees. Lot of nights the cold would just be too much." Dropping his head into his hands, he sighed gustily. "I've tried for years to get him to retire, or at least let me put in a word for him to move to the easier day shift. Damned proud old man." Lifting his head suddenly, he stared into Beckett's eyes. "What the hell happened?"

She fought to keep the relief she felt at that question to keep from showing. Too many guilty suspects never asked that question, since they knew what had happened. Then she realized that she needed to answer the question and blushed. "You know, I don't know. Once I recognized him, I just came straight over here." Standing quickly, she realized how awkward her timing was. "I'm sorry, Castle. You've got to be packing and I'm taking up valuable time."

"Aren't you going to tell me not to leave town or something since I was one of the last to see him?" he asked, a shadow of his normal self showing through.

Beckett shook her head. "I have your cell number. If I need to question you, I can find you."

A hoarse laugh erupted. "That I do not doubt." As he escorted her to the door, he put a hand on her shoulder and stopped her. "Find out who did this, okay? George was a sweet old man and a good friend. He was practically a grandfather to Alexis." His face creased with pain. "Mother's going to miss his flirting."

Beckett's heart sank. Although technically he was a suspect, she knew he hadn't done it. The pain was genuine for the old man's passing, and his loss would be keenly felt by the whole Castle household. "Listen. I'm sorry to spring this on you right before you leave." She put her hand on the doorknob, glancing at the bolts that lined the edge. "I will keep you updated, okay?"

"I know you will. It's what Nikki Heat would do."

She laughed, unable to stop it. "Absolutely. Have a good trip, Castle."

"Thanks."

Stepping out into the hall, she hesitated when she heard him locking the bolts behind her. The twisting in her gut was telling her that something was seriously not right with the writer.

Beckett really didn't remember the trip back down to the crime scene, or the rest of the processing. In fact, she seemed rather surprised when she got back to her desk and found her notebook full of notes that she'd taken. A call from Lanie had finally gotten her snapped out of her fugue.

"I don't have a COD yet, but I'm guessing it was blunt force trauma," the M.E. said by way of greeting. "There's no other marks or bruises on the body other than this gash on the back of his head."

"Why call me down here for that?" Beckett asked, confused.

"Because of this." Lanie pulled back the sheet covering the old man. She pointed to a red mark on his neck. "This was hidden by his collar."

The detective bent over to stare at the oddity. "What caused that?"

"Lipstick."

Beckett blinked. "Lipstick."

"Yes, lipstick. There was someone nuzzling up to our victim. If I had to guess, I'd say that our friendly doorman here was being hit on."

"You mean like some female lured him away from the door and then hit him on the head?"

The M.E. shrugged. "That's for you to figure out, not me."

"Thanks, Lanie."

"Kate?"

She turned back to face her friend. "Yeah?"

"What's up today? Castle's not at a crime scene, you're somewhere out in space. Something's going on."

Beckett started to deny it but thought better of it. "I don't know. There's just something about Castle that's …"

"Something's got your radar going off."

"Yeah." The detective leaned against the table as she tried to find the words. "He came in early this morning to tell me he'd be out of town for a few days. He could've just called to tell me the same message. Then when I went up to tell him about the murder, he …"

"He what?"

She shrugged. "He wasn't himself. No stupid jokes, no crass comments, nothing. I mean, he was friends with the vic, but even before that, it was just weird. And another thing. I've been to his apartment at all hours of the day and night, and he's never had his door locked. Never. Or if it was locked, it was never the deadbolts." Beckett chewed on her fingernail. "He had all of them locked this morning. I heard him open them when I knocked."

Lanie frowned. "Call the man. Ask some questions. Find out what's going on."

"What if it's personal?"

"Then he'll tell you that." The woman set her hands on her hips and frowned at the detective. "Find out the answer, and get your head back in this game. Our victim here deserves your full attention."

"You're right." Beckett sighed. "Thanks."

"Anytime. Now get out of here and find out who did this."

A smile ghosted across her face as she left the morgue. Lanie was never one to mince words. That's what she really liked about the M.E.

Glancing at her watch, Beckett realized that Castle was probably already at the airport or in the air. Promising herself that she'd call later, she forced her attention back to the case.

Ryan and Esposito had done a good job setting up the office with the known information. She stepped into her role as lead and began her brainstorming. "All right. Victim is positively identified as George Butler." She reread the name to herself and shook her head.

"What? You don't like the irony of his name and his profession?" Esposito asked snidely.

"That's not irony. That's coincidence. Irony would be if -"

"Knock it off. I got it." She continued reading through the facts. "He was last seen at his post at 7:26 this morning, which isn't inconsistent with the TOD that Lainie estimated." She heaved a sigh of relief when she realized that Castle had been with her at that time. "Who actually saw him last?"

"Um, that would be a Mrs. Greaver. She's the front desk day shift. Started her shift at 7 am and said that George was still there. She looked back and noticed him gone later, and since his replacement had called in late and George was supposed to stay until 9, she thought it was odd enough to remember the time."

"Okay," Beckett said, nodding at Ryan for his information. "Did Mrs. Greaver have anything else to say? Anyone she didn't recognize hanging around? Anything suspicious?"

"Not this morning."

She noticed the odd phrasing. "What do you mean, not this morning?"

"Mrs. Greaver has placed two police reports in the last month. One was last week and the other three weeks ago."

"What did she report?" she asked, biting back on her impatience. She couldn't believe that she actually missed Castle's snarky comments during this part of the investigation.

"One was for a suspicious person loitering on the street. Was watching the comings and goings of the tenants, and when a couple complained, she called the cops. The more recent one was for a threatening letter found in the lobby."

Beckett's gut leaped into overdrive. "What was in that letter?"

Esposito fielded that one. "Here's a copy of it. The original's still down in evidence. It hasn't been processed yet."

"I know where you live. One of these days, you'll find yourself in a trap of your own making. I can't wait to be the one to bring the storm down on you. See you soon." She froze as she read the last line again and again. And again to make sure she was seeing the signature right. "This is signed Nikki Heat."

Both men looked up at that. "You could read that scribble?"

She placed the copy on the desk. "N-I-K-K-I H-E-A-T."

"Damn. How did I not see that before?" Esposito asked. "I read that letter."

"And there's the reference to Derrick Storm. It's one of the few lines that Castle uses frequently in his books. Someone, usually the villain, ended up saying that they were going to bring the storm down on Derrick Storm." Beckett followed her gut as she began brainstorming. "So Castle has a stalker."

"Okay. Let's say the letter was meant for him. How does that connect to the vic?"

Beckett began pacing. "Castle's been down this road before. He lives a high profile life, but he has safeguards to make sure that his stalkers cannot trace him to his home. Nothing going through his publishers would lead them to the right spot. So how did this stalker know where he lived? And as to a connection, maybe George spotted the same person hanging around too often. He did work the night shift. That's when most stalkers do their work. It's possible they killed him to keep up their stalking."

"That makes sense. But why leave a letter if they didn't want him to know they were stalking him? I mean, if you take out George to hide what you're doing, why announce it?"

The pain on Castle's face rushed through her mind. "They didn't kill George to keep him quiet. They killed him to hurt Castle." She stared at the detectives. "He was a friend to the family. Castle knew him well enough to try to get him to retire. He knew he was arthritic and shouldn't be standing all night in the cold. George flirted with Martha, and he said that George was practically a grandfather to Alexis. The letter didn't get the response they wanted, so they stepped up their game."

"If you're right, then they're not going to have a problem going after Castle himself," Montgomery said from behind them, startling all three cops.

"It's just a theory, sir," Beckett said.

"But it's a theory that fits. Find facts."

"Right. Ryan, go back to the building. Start with the surveillance tapes. Particularly the day that letter was found. Esposito, get down to Evidence. That letter needs processed. It's now a lead in a murder case. That ought to get it moved up on the priority list." She paused for breath. "As soon as you're done, go back to the building. Interview anyone you can find."

Montgomery gave her a tight nod of approval. "And what are you going to do?"

"I'm going to hunt down Castle and shoot him for not telling me about this."