Disclaimer: I do not own Castle or the recognizable characters used in this story. As for other influences, please see the author's note at the end of chapter two.

A/N: Down below.

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"So," Beckett says as the door closes behind the redheads. "Two hours?"

"It's a start," Castle barely manages to say before Beckett grabs his hand and tugs him toward the bedroom.

Castle

"So, you've got a list of things you want to try?" Beckett asks while kicking the comforter off the bottom of the bed, still too hot to even have it nearby.

You walked right into this one.

"Of course I have a list," Castle pants with an eyebrow waggle. "I've been waiting years for the chance to…"

"Not that kind of list," Beckett cuts him off with what starts as a swat but turns into a chance to rub Castle's chest. "Well, I take it back. I wanna hear about that list later. But I was talking about your Gamma list."

"Oh, that list," Castle replies coyly. "Yeah, I've putting together a list of things to try."

"And how much of that list is related to what we just did?" Beckett asks with an arched brow.

Not nearly enough.

"Less than half!" Castle answers, pretending offense. "Maybe."

Huffing again, Beckett draws lazy whorls with her fingertips while Castle hums in appreciation. "What's on the other half of the list? Anything we could try tonight before Alexis and Martha return?"

"Sure," Castle answers while rolling over onto his stomach. "There's one thing that's been bothering me. Put your finger on my nexus?" he asks.

"Put my finger where?" she asks with a leer. "Oh, right, 'nexus,'" she chuckles as Castle huffs, too. Surprising him, Beckett rises from the bed to straddle Castle's thighs. After giving his shoulders a squeeze, she takes advantage of the opportunity to run her hands down his naked back, 'accidentally' overshooting his lower back to graze his behind before retreating to where his nexus resides.

God bless this woman.

"Vixen," Castle groans, pulling another laugh from Beckett.

After directing her finger until it's directly over his nexus, Castle explains what he wants to try. "I've been wondering about whether there's a vulnerability with the nexus," he says as a sphere appears above his head, suffusing the darkened room with a soft light. "I want you to picture a bubble around my nexus. If it's possible to block a Gamma by interfering with their nexus, then my light should wink out."

"I don't know, Castle," Beckett replies nervously. "I tried to rub your cheek yesterday and I almost took your head off. This doesn't seem like a good idea."

"I trust you, Kate," Castle replies with such sincerity that Beckett's gaze goes soft. "You won't hurt me. Besides, if I'm right, you won't be able to do anything to me."

"You're sure?" Beckett asks.

"Come on, Beckett, let your Gamma flag fly," Castle teases her. "I'll be fine. Just picture a transparent bubble surrounding my nexus. Are you doing that?"

"Yes," Beckett whispers, clearly still nervous about this experiment.

"It's a clear bubble, right?" Castle asks. "Now, think about it becoming opaque. It's thick, heavy, impermeable."

"You've got the sexiest pillow talk," Beckett teases to relieve some tension.

"Trust me," Castle laughs in return, the motion jostling Beckett. "This isn't what I thought we'd be doing whenever I imagined you straddling me in my bed."

"Which I'm sure you only imagined once or twice," Beckett suggests.

"Per hour," Castle agrees, "every day, for years." Still an underestimate.

Shaking her head at his ridiculous optimism, Beckett refocuses on her task and is surprised when she can almost see the bubble form around the nexus area on Castle's lower back. It's as if the humor and comfort she feels in his affections makes this easier, which it probably does.

"Okay, Castle, I've got the bubble," she says with a note of pride. "I'm going to try to make it solid."

Beckett's concentration initially yields results – she can picture the bubble growing opaque and Castle's sphere growing dimmer. But just when she thinks that she's making progress, the bubble goes transparent and Castle's light fully returns.

"Sorry, Rick," Beckett says with some frustration. "I don't think I'm doing this right."

"You're doing it exactly right," Castle disagrees. "Hold onto that bubble. This time I want you to think about it differently. We're all about running water, right? Picture a dam in your mind, all that water that wants to rush down the canyon penned up and constrained. The pressure keeps building and building," he says almost hypnotically.

Why does it feel like I'm describing us?

"You're the dam, Beckett. You're going to keep holding that water back until the water is ready to burst through. At the last moment, you're going to bring down the wall and convert all that potential energy to kinetic energy. It's going to slam down all at once and that bubble will feel almost solid. You ready?"

"I'm ready," she replies, stronger this time.

"Feel the pressure building? Just hold on, Beckett, hold on as long as you can," Castle encourages.

"Rick," Beckett whispers a few moments later, "Rick, it's time."

"Let it go, Kate," he whispers in reply.

Hope this works…

What happens next takes them both by surprise. Beckett collects the flood of energy and focuses it all on Castle's lower back. But rather than form a bubble, the energy sends an electrical shock through both of them, jolting them with energy and light and instantly extinguishing Castle's sphere. Their bodies convulse in reaction before nearly shutting down.

I think we'll keep the taser out of the bedroom from now on. Not sexy.

"Sorry! I'm sorry!" Beckett gasps as she comes back to herself moments later, finding that the jolt's left her sprawled across Castle's back. Somehow, Castle manages to spin beneath her, rolling onto his back so that he can cradle her. "My fault," he manages to say. "Thought that might happen."

"You thought we might get electrocuted?" Beckett asks incredulously, wishing she had enough energy to get properly angry.

"Well, not that exactly," Castle confesses. "But I thought you wouldn't be able to contain my nexus."

"I'm sorry," Beckett apologizes again. "I don't know why I can't seem to master the stuff that comes to you so easily. This is just last night all over again," she says in frustration.

"Hey," Castle interjects, drawing long, smooth strokes down her naked back. "Last night was just your second lesson, you'll get the hang of things. As for today, I don't think I could do this, either. I don't think we can do this to each other." At her inquisitive hum, Castle explains his theory. "We're not two Gammas, Kate," he reminds her gently. "We're one Gamma split in half. You trying to turn off my power would be like you trying to make yourself stop breathing. You could try, but ultimately your body will act to save itself."

"So why did we even try?" Beckett asks in confusion.

"Well, I wasn't sure about the split-in-half thing," Castle admits, "and because it still proves that there's a vulnerability with the nexus. If there wasn't, nothing would've happened."

"You're thinking about our killer, aren't you?" Beckett asks.

Only a homicide cop would be okay with this kind of post-coital conversation.

"How can you arrest a Gamma?" Castle answers. "How would you keep her locked up? She could just walk out, either unlocking the door or maybe walking right through it. And who knows how many people would die in retaliation?"

"So, are you trying to think of a way to block a Gamma or to remove the abilities altogether?" Beckett asks, relaxing further into him and letting her hands wander.

"I'm wondering why everything needs to be a battle to the death," Castle admits, starting let his own hands wander south from Beckett's back. "It'd be nice to think that you could remove someone's ability to cause such devastation without killing them. But maybe that would still be fatal, or maybe it would be like performing a lobotomy."

"Or like severing someone's daemon?" Beckett asks with a raised brow.

"Exactly, Lyra," Castle enthuses, pleased beyond measure by this reference to Pullman's classic. "There's just so much we don't know and it makes me nervous about catching the killer and protecting my family."

"We'll figure it out, Rick," Beckett says as she nuzzles his neck in coordination with her wandering hands. "We've made it this far," she says before her hand grabs something sensitive in a slightly menacing manner. "But you need to share these things with me," she says pointedly, though her tone is commanding less of his attention than her grip. "Ever since Calypso you've suspected that we couldn't use our abilities against each other, right?"

I much prefer when it's my ear she grabs like this.

"It was a guess," Castle squirms. "How did you know?"

"When we were talking about Calypso's threat to have you kill me, you changed the subject, remember?" Beckett asks, relaxing her grip but keeping her hand in place to rub away any discomfort.

"Busted," Castle admits, squirming now for a different reason. "But, yeah, I was wondering about that after we figured out the nature of our connection. I think it goes deeper than what we just tried. I don't think we can really hurt each other," Castle begins to theorize before Beckett cuts him off.

"Rick, I belted you yesterday," she confesses again. "You can't tell me that didn't hurt."

"It stung, sure," Castle says quickly, trying to brush past yesterday's mishap. "But it wasn't a big deal, and I'm sure in a karmic sense I've had that coming for years," he jokes, then laughs at her vigorous nodding. "But I don't…"

Wondering why he trailed off, Beckett stills her hands. "Rick?"

"Sit up?" Castle says in a resigned voice after patting her behind. Her surprise at his willful departure from their naked embrace is heightened by his tone of voice and the shirt he passes her after he covers himself with the bedsheet.

"What's bothering you, Castle?" she asks as she puts her arms through his shirt but refrains from buttoning up.

"I've got a conundrum," he starts.

"Says the author," she interjects to tease, hoping to get them onto familiar terrain and lighten the mood.

Huffing a laugh, Castle relaxes a bit. "You said you wanted me to share what I'm thinking, what I suspect about our connection," he explains while Beckett nods. "But I'm also really, really happy right now. We're together and it's even better than I imagined. I don't want to freak you out or scare you off."

"Rick," Beckett says while holding her hand out for him to grasp, "didn't you hear what I told Alexis? I'm in this. I want a future with you," she repeats her vow.

Taking her hand gratefully, he drinks her in for a few moments before proceeding. "Tell me this," he says to get started, "that first night, after the tiger – did your leg hurt?" At her nod, Castle nods, too, then continues. "When you and the boys were kidnapped, I nearly passed out. I felt it when they bashed you on the head. I'd bet your cheek hurt yesterday, too, though probably not enough to notice with everything else going on."

"But we know this already," Beckett soothes. "Our connection helps us feel what happens to each other. It saved my life," she says sincerely, before her face takes on a decidedly devilish look, "and the bedroom implications are staggering. Literally."

"I know, right?" Castle says with a laugh. "I'm glad to hear it's not just me! But that's the good side. I'm starting to wonder," he says as he looks at their clasped hands, "about the cost, especially for you."

"Come on, Castle, just say it already," Beckett cajoles in exasperation. "You're worried that we're tied together irrevocably, that if one of us were to die it would kill the other." Noticing that he's gaping at her, she just shrugs. "It's the obvious conclusion, right? We're stronger because your power is distributed to both of us, which helped against Calypso. But we're weaker, too, because we'll both die if one of us is killed."

"You're okay with that?" Castle asks in confusion.

"Castle, I'm a cop," she clarifies for him. "I've lived with the chance that someone would kill me for the entirety of my career."

"I know you're okay with the risks, that's not what I'm talking about," Castle replies with some frustration. "I'm talking about us – you didn't ask for this, Kate. I did something to you without your permission that's left you stuck with me 'irrevocably,' as you said."

Please don't run.

"Yes," Beckett interjects fiercely. "Yes, you did – you tried to take a bullet for me, even though we weren't together yet. And you saved my life. And you gave me the space I needed to heal, inside and out. But above all, you stayed – from the very beginning, you proved to me that you'd be there for me. So, yes, Rick, we're irrevocably tied together," she vows, pulling his hand toward her and holding it in place over her heart. "And it has nothing to do with mystical powers or obligations. It's because you made it impossible not to fall in love with you."

Stunned by her words or trying to commit them to memory, Castle sits in place while his eyes rove over her form, from her eyes to the heart beneath his palm. "God, I love you," he whispers.

"Good," Beckett says resolutely, "'cause you're stuck with me. Now come on, handsome," she says while reclaiming his hand in hers and tugging him toward the edge of the bed. "It's still early days with Alexis and I don't want to overdo my presence before she's used to us. So, Mr. Running Water, let's go investigate the restorative powers of your shower before I need to leave."

Beckett

"Just calling to tuck me in?" Beckett asks with a smile as she cradles the phone to her head.

Not that I would've slept without hearing from you.

"Of course," Castle replies. "It's all part of the experience. It'll be easier when I can do it in person, though."

"Yeah, it will," Beckett replies softly, surprising them both with her candor. "How's Alexis?"

"She's…," Castle trails off. "Honestly? She's confused and hurt and scared. But, she talked to me. Just a little, but it was enough to make us both feel a little better. Good enough to get at least a little sleep tonight, anyway."

"I'm sorry, Rick," Beckett replies ruefully. "This would be so much easier if I'd treated you differently…"

"Hey," Castle interjects, "we both made some mistakes, but we're here now. And if I haven't mentioned it, I'm very, very happy with where we are now. She'll come around. Sooner, if I can stop being such a jackass."

"Hey, now who needs to go easy on himself?" Beckett cajoles.

"I really scared her," Castle says in a low voice. "Not with the… family medical condition stuff," he fumbles, unwilling to talk about being a Gamma on the phone, "but with my comment about letting her live with Meredith. She wasn't thinking that way at all and my comment made her think that a part of me might want her to leave."

That poor girl. We've got to find a better balance – I don't want to be responsible for harming their beautiful relationship.

"Oh, Rick," Beckett laments. "We can… I don't know, slow down or take a break if she needs some time to make sure she's okay," she offers, though her distress at doing so is apparent.

"No, Kate, no," Castle soothes in reply. "We just need to ease into things, let her see us together. If anything, it might help to see you around a little more."

"Well, if that's what the doctor orders," Beckett says in a more cheerful voice, trying to make things lighter before they retire for the evening, "then how can I argue?"

"Sure," Castle huffs, "wait until after you leave to start talking about playing doctor."

"Just add it to the list," Beckett suggests, turning his pout into an exuberant laugh.

"Fair warning, Beckett," Castle warns, "I'm looking for excuses to make the list longer."

"Excellent," Beckett replies happily. "Hey, Rick?" she asks after his laugh of agreement. "Thank you," she says earnestly. "For your faith in us, for inviting me into your family."

"'Course," Castle replies. "It's where you belong."

After Beckett's pause makes him wonder if she's embarrassed, Castle tries to lighten the conversation a bit. "Speaking of family, our newest member still needs a name."

"Did you buy a hamster, Castle?" Beckett asks.

"Ew, no," Castle replies in distaste, providing fodder that Beckett tucks away for future teasing. "I talked to Bert the boat guy after you left. We're all set for a delivery a week from Friday. But, we've only got three days left on her name for the paperwork. I told him you'd call."

Time to pay up for the yearbook, partner.

"So, you're really giving me the naming rights?" Beckett asks in amusement, setting the trap.

"That was the deal, right?" Castle answers impishly. "You criticize the old names, you have to come up with the new one. Pressure's on, Beckett," he taunts. "Bet you're realizing how good those names were now, right?"

You asked for this Castle. Over and over again.

"Actually, Rick," Beckett replies with a tone of slight defeat, "I was wondering if you could provide some advice."

"No, no, no," Castle replies, and Beckett can almost hear his waggling finger. "No cheating. This is your responsibility, partner."

"Okay," Beckett agrees. "But there's no rule against thinking out loud and making note of any aural cues and reactions. How good are you at masking your reactions, Mr. Poker Face?"

"Excellent, obviously," Castle replies haughtily.

Sucker.

"Well, I'm sure articulating my thoughts will help me make some decisions anyway," Beckett says reasonably. "I've got three categories of names I'm thinking about, though they're not mutually exclusive."

"You even make naming a boat sound sexy," Castle marvels in an undertone, but Beckett continues despite the distraction.

"First, I'm reminded that my friend Jonas will spend most of the time on the boat, so we need something fitting for him. Something that characterizes his personality. So, this category includes sweet, girly, precious things. Princess Fairy Unicorn, maybe, or Tinkerbell's Toy, something like that," Beckett says with an admirably straight face. Castle manages to remain silent, though she can hear him shifting uncomfortably.

"The second category," Beckett continues, "is a little more creative. You've helped me realize in the last few years, Rick, how good it feels to challenge convention, to cut loose a little."

Though he may act it occasionally, Castle's no fool. He suspects a Beckett trap and sits quietly, waiting for the boom to fall.

You ready, Writer Man?

"So, I was thinking that the second category would be names that defy the tyranny of grammatical conventions and spelling customs. I have many, many options here, names like Your Invited or Look Whose Talking," spelling the names out to ensure his understanding.

"You wouldn't…" Castle can't stop himself from moaning.

Ignoring his dismayed reaction, Beckett plows on. "But the third category, Castle…," she says with a raised brow. "The third category might be the best. Do you remember how pleased I was last time we had a conversation about names?"

Beckett knows he's on the same page when a small groan signals his horrifying realization. "Nikki. Heat. A stripper name, Castle," Beckett reminds him, "and one that you resolutely defended in the name of artistic integrity. I confess," Beckett says in a tone simulating contrition, "that I didn't understand your fierce stance on the name back then, but I do now. I mean, the names in this category, they just speak to me, you know?"

She pauses to allow Castle a chance to respond, but he's uncharacteristically silent.

"Patterson's Pleasure has kind of been growing on me," Beckett admits. "It's got alliteration, an allusion to literature, and it helps us hide, right?" Silence. "But my favorite in this category is probably Kitten's Kruiser," Beckett muses. "That one checks the boxes in all three categories if we spell it right, by which I mean wrong."

Poor Rick, I imagine you're looking a little green.

"So, Mr. Castle," Beckett asks in her detective tone after a few more moments of silence from Castle, "would you care to revise your statement?"

"About giving you the naming rights or about how you can't threaten me?" Castle laments.

"Your phone 'poker face' perfectly masked any reactions, so I'd welcome any advice you have to help me resolve my naming dilemma," she requests as she chooses not to glory too much in having turned the tables on him.

Beckett can imagine the squirrels darting around in his head, scurrying madly to find the one nut of an idea that might salvage this situation for him. She also hears the moment he comes to a decision. "If you're going to be there with me, Kate," he says quietly, "then the name doesn't matter."

Damn you, she thinks affectionately, marveling at his answer.

"Love you, partner," Beckett huffs affectionately. "Now go dream of me."

"I have for years," Castle confesses.

Castle

She looks more beautiful every time I see her.

"Her name was Lisa Economides," Beckett says as she accepts a cup of coffee from him, boldly stroking his fingers in the handoff.

"Who?" Castle asks, confused by the quick start and maybe dazzled by the quick physical connection in the midst of the precinct.

"Calypso," Beckett answers quietly, sliding a piece of paper across the desk to him. "I checked Missing Persons on a hunch. She has a sister – Diane – who works for Deloitte, splitting her time between New York and London. She just filed a report."

Either you're an even better actress than I thought or you've taken compartmentalizing to a new level.

"Are you okay with this?" Castle asks in a low tone. When Beckett casts him a confused look, he explains. "You've built a career around providing closure and justice to the families who've lost loved ones," he says gently. "But we know Diane's not going to get closure."

"No, she won't," Beckett agrees. "But justice? Her sister tried to kill us, Castle," she whispers. "And you tell me, since I've got no frame of reference – how strong was she? Can you tell if she'd killed others before coming for us?"

Glancing down at the report on Lisa Economides, Castle frowns. "She was only 28. She wasn't nearly as strong as the woman who killed Joseph, but she wasn't weak, either, or inexperienced." With a sigh, Castle capitulates. "I don't really know," he admits, "but I'm pretty sure she was much stronger than she could've been on her own."

"So, she was a killer, Castle," Beckett summarizes, "a killer who died while trying to kill us. Do I feel good about what happened? No, and I hope I never become numb about what we had to do," she says in a somber voice. "It'll be hard, accepting that her sister won't have the peace of mind from knowing her Lisa's fate, but it's the price we pay, because of who we are and what we do."

Being okay from afar is different than what we'll need to do, though.

"Can you face her? The sister, Diane?" Castle asks gently.

"What do you mean? This isn't a homicide case," Beckett answers with a penetrating look, "and it would be odd for us to get involved in a Missing Persons case unless the evidence suggested a murder."

"I'm not necessarily suggesting official involvement," Castle clarifies, still in a low voice. "This says Diane's holding a vigil on Thursday night if her sister isn't found by then. The more noise she makes about her sister's disappearance, the more vocal she is about how wonderful and successful her sister was…"

"The more likely the killer we're looking for might recognize the reason for Lisa's disappearance," Beckett finishes for him. "And if that happens…,"

"Then he might come for Diane," Castle nods. "In fact, we could bait the killer," Castle continues. "Not at the vigil, but later. We'd have to get Diana out of the picture," he says with furrowed brow, "but just assume that we can figure out how to do that. Then we could flare a little Gamma power from her apartment, make any observer think that the trauma of Lisa's disappearance freed Diana."

"Seems like a longshot," Beckett thinks aloud, "but we don't really have any viable leads. Gates is already acting as if this is a tally in the loss column."

"Even if we're right," Castle says, "it'll still be a loss as far as the precinct closure statistics are concerned. If we find the killer and he's a Gamma, then…"

"Poof," Beckett supplies.

"Poof," Castle agrees, "unless there's some way to shut down his nexus."

"You know the biggest challenge to your plan, right?" Beckett asks with a perched brow.

Can't be a bigger challenge than getting you to believe in it!

"The boys," Castle answers. "Well, technically, anyone official. It's going to be difficult to explain why we're staking out the sister of a Missing Person who had no connection to your homicide case."

"We don't want a connection," Beckett replies, surprising Castle. "If Lisa's disappearance is linked to Gamma activity and then connected to a homicide that a Gamma might recognize, it'd be hard to hide that there are people in the precinct who know about Gammas."

She figures things out without even knowing she's doing it – talk about a natural detective. Time to fess up, before things get uncomfortable.

Castle nods, a faraway look in his eyes suggesting that he's deep in thought. "You're right, of course. It reminds me of something else I've been thinking about," he confesses. "I guess I should probably tell you about it before risking any bodily injury," he says while letting his eyes drift down, reminding them both of her threatening grip the night before.

"Good idea," Beckett agrees with a nod.

"I was thinking about what you just said – signaling that someone in the precinct would know about Gammas. I don't know much about us or our history, but if our skills are inherited, then it's unlikely that Gammas are relatively new. And if Gammas aren't new, how likely is it that we've escaped notice over the decades or centuries?"

"I don't mean this to be flippant," Beckett prefaces, "because I know we're talking about something serious. But I'm in a relationship," she whispers, "with my favorite author. So, tell me a story?"

You have no idea how long I've wanted to hear that.

"It's not so much a story as a collection of musings," Castle confesses. "Story ideas, maybe. But look at history – there've been exceptional people whose amazing accomplishments might make more sense through the Gamma lens."

"Are you going to tell me that miracles were acts of Gammas, that our modern religious traditions are built on a foundation of Gamma activity?" Beckett asks.

"No, no, no," Castle says quickly and emphatically. "Beckett, I can already smell sulphur and brimstone – there's no way I'm going to actively provide any more reasons for any deity to have it in for me. Other than pre-marital sex, of course," he says with an eyebrow waggle.

"Pre-marital?" Beckett asks with a perched brow.

"Just focus on the sex part for now," Castle encourages her. "We'll talk about the marital part later."

"Sooner," Beckett corrects him. At his flummoxed look, she clarifies. "'Later' sounds too indeterminate, too far in the future to be reliable. We're not there yet, but I'd prefer we talk about it sooner rather than later."

"Sooner's better than later," Castle replies with a stunned nod. "I like sooner. I love sooner."

"Good," Beckett says crisply. "If not religions," she asks to get them back to their discussion, "what historical aspects of Gammas were you thinking about?"

"My thoughts started with certain historical figures," Castle explains, still looking pleasantly dazed. "Doesn't Rasputin seem like a likely suspect? He was even smart enough to play puppet master. Or what about Nostradamus, or Joan of Arc, or…"

"Merlin? Agrippa? Ptolemy?" Beckett suggests.

"So. Freaking. Hot." Castle mumbles, before shaking his head to get back on track. "But then I got to thinking about people who could've been Gammas on behalf of their country, as an extension of diplomatic or military might."

"Examples?" prompts an intrigued looking Beckett.

"How did Trotsky wake up with an icepick in his head 2,000 miles away from Moscow? Was it really an umbrella that delivered a ricin pellet into Georgi Markov in London, or tea that irradiated Alexander Litvinenko?" Castle asks. "I bet some of my conspiracy theories don't sound quite so implausible anymore. Who would make a better spy, or spy catcher, than a Gamma?"

James Bond would still kick a Gamma's ass, though.

"You're right, Castle," Beckett says, prompting a premature look of shocked delight from Castle. "I'm not agreeing with your conclusions," she clarifies with an eye roll, "just with the idea that this is an interesting thought experiment. But how is this relevant to our case?"

"It's not," Castle agrees, "or at least not directly. What it comes down to is this: we need to be careful about being discovered from within as much as from without. I don't want to get press-ganged into foreign service or find myself the prime specimen in a government lab."

"Oh, come on, Rick," Beckett teases, "I bet you always imagined seeing Area 51."

"Sure," Castle agrees readily, "but not from the inside."

"I suppose that tricks like Calypso's disguise would've come in handy during the Cold War," Beckett concedes, thinking again about the nation-state implications of what they can do.

Nodding vigorously, Castle picks up his theory. "It also explains the explosion of security and surveillance cameras," he says. Spreading his hand on his knee, he looks to Beckett. "Check out my hand."

"Castle!" she hisses in a whisper. "We're talking about keeping a low profile. I think a detective might notice that you've got six fingers!"

"Not if you're quiet about it," Castle teases with an eye roll of his own. "Grab your phone. Hold it like you're checking a text, but look at my hand through your camera app."

Hiding a look of consternation, Beckett does as Castle suggests. Getting more accustomed to these little tricks, she doesn't gasp when she understands the point of his demonstration. "Five fingers. So, the illusion must act on human senses, leaving electronics and cameras unaffected?"

"That's my theory," Castle says, "and my theory on the rapid introduction of security and surveillance cameras. But if I'm right, now we've got another problem."

"Aside from understanding the limitations in disguising ourselves?" Beckett asks. "Oh, damn – the precinct cameras. There'll be footage of Lisa Economides walking into the precinct and riding the elevator."

"Yep," Castle agrees. "Is there a camera covering the bullpen?"

"No," Beckett says, "but that won't help. You'll be on camera leaving with her. Maybe we could…"

"Hold it, Beckett," Castle asks quietly. "Don't say any more. I know where you're going and we need to be careful about how far we're willing to go here, especially under the nose of a captain who used to be in IA. If someone tracks her to the precinct and if someone finds the elevator footage, I'll play the playboy card. She was just some fan who somehow walked right through security and up to the homicide floor, and I left with her to get her out of the building before Gates scalped me. Easy."

"But what if she left notes of your appointments or about you where she lived?" Beckett asks, starting to understand the other side of her homicide investigation.

"I doubt that – I was going to be her meal and she wasn't big on sharing. She wouldn't leave anything behind that might lead other Gammas to me. And, even if she did, it would be all one sided – research on me, my family, my life. It'd look like a stalking situation. Let me make some calls," Castle suggests vaguely. "Worst case, it'll have to be one more example of an obsessed fan or one of Richard Castle's ridiculous flings," he sighs. "A fair number of those were fictitious anyway, so one more won't matter."

"Just as long as there are no new ones going forward," Beckett challenges, though the lilt of her voice conveys affection, maybe even confidence.

"No new ones," Castle agrees, "just the one I've recently, finally embarked upon," he says with a phantom kiss to her cheek. "I'm a reformed Bumble."

"Damn straight," Beckett says happily. "Now, stop distracting me. We need to think about how to figure out the details of your plan in parallel with pursuing a more traditional investigation for our vic."

"That's easy," Castle dismisses with a wave of his hand and a mischievous glint in his eye. "It's what we do on every case, right? You do all the hard work, the methodical review, the dissemination of evidence, the investigation. And then I come up with the right answer."

"Hold still, Castle," Beckett suggests sweetly. "I want to caress your cheek again."

A/N2: Many thanks for the reviews, including the Guest reviews that have been so interesting. They're all appreciated!

On a more somber note, Pray for Paris. Sometimes I just don't understand our world.