A quick search of Janine Stafford revealed nothing. Only when that was done was she allowed to sit in a chair in the billiard room.

"I know how this looks..." she began.

"Then you know how bad this is for you," Castle said.

"Yes, I know, it was stupid, but I didn't kill my dad. You have to believe me..."

"You haven't given us any reason to," Beckett said. "What were you doing here? What was so important that you had to break a police seal?"

Janine Stafford's eyes shifted from left to right and back, at least twice. "I... I had to know," she finally said. "I had to. If I had to spend one more night not knowing, I thought I'd go insane..."

"Know about what?"

Stafford exhaled. "I got divorced last year. Do you know why?"

"No, why?"

"My husband was cheating on me. I got photos, anonymously, in the mail. I never found out who sent them, but you know who I always suspected?"

"Your father?" Castle guessed.

She nodded. "He always thought he was doing what was best," she said cynically. "No 'road to hell is paved with good intentions' for Nathan Stafford, oh no! He'd do whatever it took to rescue people from their own mistakes, because he was 'just trying to help'!" She wiped at her eyes with trembling fingers. "The photos were professional. My dad always denied that it was him, but who the hell else could it have been? I had to know," she repeated. "I had to know if Dad took Allen away from me and meddled in my life yet again..."

"So you were looking for evidence that he hired a private detective to follow your husband and catch him cheating?" Castle said.

"Maybe he tricked Allen into cheating! I don't know! That's the whole problem! I wasn't thinking!" Janine Stafford burst out, stating the obvious. "I've been obsessing with this ever since the divorce was final. My therapist kept telling me to let it go, and I know he's right, but I couldn't help it..." She buried her face in her hands, the rest of her words dissolving into nothingness. Beckett and Castle waited, with varying degrees of patience, until her face lifted once more.

"Since we have you here," Beckett said with more than an edge to her voice, "you can tell us where you were between eleven pm and midnight on the night of the party."

"Everywhere," she said. "The dining room, the parlor, the kitchen, upstairs... I don't think I stayed put anywhere more than ten minutes."

"It wasn't your party," Castle observed. "Are you always like that?"

"As a matter of fact, yes," Janine Stafford said stiffly. "I'm a bit of a control freak, I admit. Besides, like I told you, I was helping my dad with this party. I wanted to make sure everything was going smoothly."

"But that also means," Beckett pointed out, "that you don't have much of an alibi. You were in and out so much that it's impossible to put together a steady timeline of your movements."

"And I made things worse for myself by coming here," Stafford finished. She heaved a deep sigh. "My dad and I had our... differences, and he could be a controlling bastard himself sometimes, but I didn't kill him. I didn't need his money, and despite everything, I did love him."

"Then do you have any ideas on who did kill him?"

Stafford shook her head. "None."

"Ms. Stafford," Castle cut in, "was last night the first time you've been to this penthouse?"

"Yes. It's the first time any of us had been here, except my dad, and he only poked his head in once in a while to check on its progress."

"Up to last night, who'd been here?"

"Just decorators and movers. Oh, and cleaning staff; they gave this place a thorough cleaning from top to bottom the day of the party. Everyone who worked at the firm came here directly from the office after closing. Why?"

Beckett was asking the same thing with her eyes. Castle shrugged. "Might be important. When was the last time you saw your father alive?"

"About ten past eleven. I went to his study. To... you know... look. But he was there, behind his desk; I didn't expect him to be. So I just pretended I was looking for him to ask him a question about the dessert tray. We didn't talk for long — just a minute or two — and I left."

"Then maybe you can help us, and do yourself some good." Beckett held out a hand, and Castle handed her a folder. "These are photos from the crime scene. If you can, I'd like you to look at them and tell me if you notice anything unusual."

"I'll try." She shuddered upon seeing the gruesome photos. Almost immediately, she frowned.

"What?" Beckett asked.

"That... that statue..." Her finger tapped on a still image of the bloody obelisk on the desk. "I don't remember seeing that when I talked to Dad last night."

"Could it have been elsewhere in the room then?" Castle asked.

"I suppose, but if so, why would Dad have moved it so suddenly?" It was a good question. "Besides, I think I would've remembered if he owned something Egyptian; I'm interested in its art because of— Oh!"

Beckett's spine straightened. "What is it, Ms. Stafford?"

"U-Uncle Grant. He just came back from a vacation in Cairo. He's the only person I know who's been there lately."

Beckett nodded slowly. "We'll follow up on that. Thank you, Ms. Stafford." Automatically, Janine Stafford rose as Beckett gathered up the photos. "No, sit down. You still have your actions today to answer for."

"I... I know. Do you mind if I call my lawyer?"

"Not at all."

"CSU did a quick sweep of the penthouse," Esposito said later at the precinct. "As far as they can tell, Janine Stafford didn't do anything to the crime scene or the rest of the penthouse. Nothing missing or altered."

"She wouldn't have been able to dispose of anything anyway," Beckett mused. "Not with how quickly we found her. And her lawyer's already bailed her out. Knowing that family and their influence, the charges we have against her probably won't stick. Not unless she killed her father."

"Speaking of the crime scene..." Castle muttered, "I've been looking at some of these photos, and... You see the bloodstain on Nathan Stafford's right index finger?"

Beckett looked over his shoulder. "Yeah, I noticed that. Too much to just be spatter from the attack..."

"Right. And didn't the autopsy report say Stafford could've survived the blows to the head?"

"Could have. He definitely wouldn't take long to die from them even if he did."

"Then I wonder..." Castle began flipping through the crime scene photos, specifically the close-ups of the desk. "If this were a Golden Age mystery, this would be the perfect setup for... Aha!" He plucked out one of the photos and waved it triumphantly in the police detectives' faces. "A dying message clue, right out of Ellery Queen!"

All three leaned towards the photo. Indeed, painted onto the surface of Stafford's desk, near the edge, were two parallel lines in blood. "Hm, I see," Beckett said. "You can just make out fingerprints in those... I'll bet they'll match Stafford's... How did I not see that before?"

"There was a lot of blood there," Castle said with a shrug. "It just sort of blended in."

Beckett shook her head. "Yeah, but that assumes that this is a dying message to begin with. Even if it is, what does it mean?"

"Good question." Castle flipped the photo back to face him. "Could be an eleven. Or a Roman numeral two. Ernie Stafford, the second child?"

"But you're assuming that Stafford meant to draw them at that angle," Ryan pointed out, taking the photo from Castle and turning it 90 degrees. "Now it's an equal sign."

"Equal sign..." Castle mused. "Grant Tate is Stafford's equal in the firm..."

"Or it could be a double slash," Esposito said, tilting the photograph slightly. "Maybe he was gonna write a Web address or something?"

"This is all speculation," Beckett said. "And weak speculation at that. So why don't we concentrate on what's right in front of us right now?" She tapped her chin in thought as she stared at the main crime scene photos posted on the whiteboard, at the desk and walls around it, practically sprayed with the victim's blood as if by a lawn sprinkler. "Like that one big nagging question... Any ideas on that one, Castle?"

"Not yet, but I'm working on it." He hopped off the desk he'd been sitting on. "We still have two more suspects to interview. Want to split up?"

"Sure. I'll take Grant Tate."

"Perfect. That leaves me with our most likely suspect."

"Zachary Evans? How's he our most likely suspect?" Esposito asked.

"Because he's the least likely suspect," Castle replied. "As the only one with no apparent motive. It's never the most likely suspect in Golden Age mysteries."

Ryan's brow furrowed. "Yeah, but... Once you know that... If him being least likely makes him the most likely... Doesn't that make him the least likely again? And circle him back to being most likely? Over and over again?"

"Exactly!" Castle crowed. Esposito and Beckett exchanged puzzled looks.

"Okay, then," the latter said. "After we're done, let's meet back at the penthouse. I want to take a closer look at your 'dying message.'"

"Ah!" Castle said, puffing out his chest. "This is a good day to solve a murder! I feel it, Beckett: we're close!"

"I hope you're right. This case is starting to get to me."

Grant Tate sighed, leaning back in his his plush office chair. "Yes, Detective, I did give Nathan that obelisk. The night of the party, in fact, not long before we..." He shook his head slowly.

"You didn't mention this last night," Beckett said pointedly. "You had to recognize it when you saw it."

"I did, but... I suppose I was hoping no one would notice it was new. Stupid of me, I guess."

"Yes, it was. It makes me wonder if you have anything more to hide."

"I know my word isn't worth much, Detective, not in a murder investigation, but there isn't anything else. Nathan and I were friends for decades. I have no reason to kill him."

"Not even for sole control of this firm?"

"I don't need it. I'm living comfortably enough, and so is my family. I was satisfied with what I had."

"So you say."

"No, nothing will really change for me," Zachary Evans told Castle as the latter followed the former into the high priced steakhouse where a business lunch was about to take place. "I always worked directly under both Mr. Stafford and Mr. Tate. I just have..." He skidded to a stop. "I just have one fewer boss now," he said quietly. He rubbed sweat off his upper lip as he sat at a large table. No one else was there yet, so Castle sat next to him.

"No ambitions for a higher pay grade?" Castle asked.

Evans smiled tightly. "If I did, I would've asked for it a long time ago, and gotten it. Or I would've struck out on my own already. But I like Stafford and Tate. It's my home. It gave me my start, and I'll always be grateful to it for that — and to Mr. Stafford and Mr. Tate for giving me a chance."

"So when was the last time you saw Nathan Stafford alive?"

"Actually, it's kind of funny..." Evans grimaced. "No, not funny, that's the wrong word for it. You see, Mr. Tate and I were the first people to find him dead, but we may have also been the last people to see him alive too."

"Zachary and I were playing pool in the billiard room," Tate said, idly toying with an expensive fountain pen as he spoke. "Until about twenty minutes past eleven. We went together to Nathan's study to see if he wanted to play a round with us. He didn't, but he promised he'd join us later. That's why we went looking for him at midnight."

"And that's when you gave him the obelisk?" Beckett asked.

"Yes. It was a housewarming gift. He seemed to like it. Said it would make a nice decoration for his desk. And he was right; there was nothing else on it except for a lamp and a blotter." He smiled, a fond and sad smile. "Nathan was never one for hoarding possessions like a packrat."

"How long did you three talk?"

"Five minutes, maybe? Not more than ten. After that, I went downstairs to get a drink, then I went out to the first floor balcony to get some fresh air. I took a look at the pool and admired the view."

"Can anyone vouch for that?" Castle asked.

Evans shook his head. "Probably not. It's a big balcony, and people were going in and out that entire half hour."

"I stayed upstairs, in the billiard room. I practiced a couple of shots, then had a drink. I was there until Zachary returned a little before midnight."

"And you were alone that entire time?"

"Yes. There was no bartender there, so I fixed my own drink."

"Can you think of any reason anyone would want to harm Nathan Stafford?"

"None at all."

"I noticed when we first met that you seemed to want to say something when Mr. Tate said that there was no business related reason to kill Mr. Stafford," Castle said. "Mind telling me what you were thinking?"

Evans hesitated. He looked around for a moment to make sure no one was paying attention; Castle's curiosity piqued. Finally, he leaned over the table towards Castle and spoke in a harsh half-whisper. "Okay, I'm not supposed to know this, but I have a... contact at the SEC. They're gearing up to open an investigation on Stafford and Tate employees. They think someone there is engaging in insider trading."

Castle raised his eyebrows. "But they don't know who?"

"No. Whoever it is covered their tracks pretty well. But the patterns, the connections... Whatever they've got, it's too strong to ignore."

"Who else knew about this?"

"Only Mr. Stafford. I told him what I'd heard last week. He promised he wouldn't tell anyone else; my contact could get into major trouble if anyone knew he'd so much as hinted..."

"So you think that's what he was thinking about the night of the party?"

"Maybe. It's a strong possibility, anyway."

"Any guesses who's responsible?"

"No idea."

"Oh, and Detective Beckett..."

"Yes?"

"Please don't be too hard on Janine. I've known her all her life, and what she did... It wasn't like her."

"So you don't think she killed her father?"

"Of course not!"

"What about the others?"

Grant Tate rubbed his eyes. "Honestly, I can't imagine any of them doing something like this. Ernie's always been a good kid. Zachary's a fine young man himself. And Iris... She has a job at Stafford and Tate as long as she wants it. That's how highly I think of her."

"Despite her affair with your best friend?"

Tate winced. "I thought it was stupid, frankly, for the lawsuit potential alone, but Nathan was a grown man. Besides, I actually saw a little bit of the old Nathan the past year — the one I knew before Rita died."

Beckett rose. "Well, thank you for your time, Mr. Tate."

"No problem." Evans looked hesitantly over Castle's shoulder. He followed the gaze; a group in business attire, a few of whom seemed familiar from the party, had just entered. "Uh, if there's nothing else?"

"No, nothing, for now. Thank you, Mr. Evans." Castle left the restaurant deep in thought. He remained deep in thought the entire cab ride to the fatal penthouse, deep enough to not notice the greeting from the uniformed officer stationed in the lobby. He only returned to the real world when he met Kate Beckett in the second floor hall.

"Okay," she began, "let's go through the killer's movements. Since the door to the study was locked on the inside, he would've had to come in from the master bedroom."

"Right." The two stepped into it, a luxuriously appointed room decorated in rich browns and tans. "The killer would've had to know that he was working on a short time frame. He could've locked the door to the master bedroom, but there was no guarantee someone wouldn't have noticed. That may mean premeditation. Kind of risky, regardless, killing him in the middle of a crowded party, not knowing who could show up looking for their host."

"Which is why I like your insider trading motive," Beckett said, pacing the perimeter of the room. "The killer could've discovered at the party that Stafford was closing in on him, and knew he had to act fast."

"Any of our suspects in deep debt, or need cash in a hurry?"

"Not that we've discovered yet, but if there's one thing I know about Wall Street, it's that once you get a taste of the good life, it's easy to want more."

Castle idly opened a drawer. It was empty. So were the others, and the closet. "Huh. Looks like Stafford wasn't fully moved in yet."

"Let's move on. The killer goes through the master bathroom..." This room was covered in marble, with gold plated fixtures and a shower that Castle usually saw only in fancy spas. Castle opened up a wicker hamper, and lifted out a damp bath towel, peeking underneath it. There was nothing else inside. He then went to the medicine cabinet; it was fully stocked with everything from ibuprofen to Q-tips. "And then to the study."

Castle and Beckett paused in the doorway. The study desk was in direct line of sight. "There's no way someone could've crossed the room without Stafford noticing."

"Right. Which supports that the killer is someone Stafford trusted."

"Anyone else enter the study, or the master bedroom or bath?"

"Just our five suspects."

They went over to the desk; on its surface, near the bloodstained office chair, were the two parallel lines, painted onto the desk in blood. "Fingerprint match Stafford?" Castle asked as he leaned in closely towards them.

"Yep. Although that still doesn't prove that Stafford made them. The killer could've done it to throw us off the track."

"If that were the case, he probably would've done something more transparent than this. He would've tried to directly and unmistakably implicate one of the other suspects." Castle tilted his head this way and that. "Still not seeing anything."

"Could be there's nothing to see," Beckett pointed out. "Who knows why Stafford made those lines? You know as well as I do that life doesn't fit neatly into place like books do."

"Yes, I know, I know. But there's something there. I know it. Maybe Stafford was trying to draw an arrow? But if so, which way did he want it to point...?"

"I think you should give up on those lines, Castle. You're still overthinking it. There's no way Stafford could've had any of that in mind, not after several blows to the head."

"You're right," Castle said, frowning. "That's the problem with dying message clues. Normal people can't think about roundabout symbolism or complex messages while they're dying. All they'd want to do is..." Castle almost gasped, his back straightening. "All they'd want to do is..."

"Castle?"

"Just a second, let me... But is there any...? Of course!" He slammed his right fist into his left palm. "The little grey cells..." he said smugly, turning to Beckett, "have done excellent work today."

"And I'm sure you're dying to explain," Beckett said with a wry smile.

"That I am."

And he did explain. It took several minutes, and several back and forths with Beckett over points here and there, but by the end of it, Beckett was nodding her head.

"I think..."

"Yes?" Castle asked eagerly.

"I think you're onto something." Castle did a fist pump. "But you realize that none of this is actual evidence that'll stand up in court."

Castle deflated. "Yes, well... Usually writers get around that with some kind of clever trick or confession..."

"Like I said before, Castle, we're going to catch this killer with solid police work. If you're right, there's one place we can start looking for evidence right now." She took out her phone. "I'm calling CSU to take a closer look. They didn't have much reason to examine it closely before, but maybe they can still find something. I'll also get Ryan and Esposito started on warrants..."

"You know," Castle said as she held her phone to her ear, "if this were a mystery novel, this is the point where I'd turn to the reader and challenge them to solve the mystery. I'd tell them they have all the clues, and they can try to piece it together just like I did. Maybe I'd mention that the key was indeed that big unanswered question that we all saw earlier..."

"Castle? There's nobody here but us."

"Right. Sorry."