"I remember reading this article a while back," John shares as they're driving. They are the first words spoken for several miles. "It's a doctor describing a psychiatry program being developed in Russia. Art-therapy."

Beckett glances over at the deputy. They've evidently been pondering the same thing. Namely, how Castle changed the spider into a man—a deeply agonized man—in as little as seven minutes. "Sorry to interrupt, but you realize Richter was probably reacting to our aggression initially, right? Neither of us was exactly hiding it. We went in there on attack mode." Her voice quiets some. "I know I did anyway."

John shifts guiltily in the driver's seat, mutters, "Yeah. Me too. Hard to accept any murderer sitting there free and clear like that, even one that's been theoretically punishing himself since."

"Hard," Kate agrees. "He must have seen that," she continues, more thinking aloud, "and it pushed his buttons. More cops at his door, with new questions, but the same ol' contempt. He knows about you from the local community and me from Castle's books—some idea of me anyway. He was prepared ahead of time to blackmail us, but now I wonder if he would've done it if we'd behaved differently from the get-go. Martha being there was just one more unpleasant reminder. Even Castle might've been in a small way; he is a wealthy citizen of the area."

"What's your point?"

"No point exactly," she replies, sighing tiredly and rubbing two fingers into the corners of her eyes, "just curiosity. Maybe Richter was reacting to us inside. Maybe on a normal day he really is closer to what we witnessed outside: a broken doll consumed by guilt. That recording equipment in his house probably serves a legitimate function. I've seen setups like that before at firing ranges. The instructors use cameras to observe their pupils' technique from multiple angles. It's not an uncommon tool in any field these days. Makes just as much sense for a piano teacher."

"I could buy into the video part. Maybe I can even accept that he's not normally monster or man, but some tortured hybrid of the two. Even if that's the case though, I still think you're reaching, Kate."

"What? Why?"

"Because this isn't about Richter. You're talking about him, but what you're really trying to do is explain Castle's music in a way that makes more sense. That article I was trying to tell you about raises similar questions. It did for me anyway. It explains how art, including music, can be used in therapy to excite emotions, increase physical energy and mental well-being. It tells the physiological how and why of it all. But despite an offer of empirical evidence I feel like science isn't fully equipped to explain this. Some concepts defy analysis. They only make sense in a human heart." They slow almost to a crawl before making a right turn. Even amidst such cautionary speed the ass end of the truck slips to one side before John straightens them out. "I wish I'd taken the time to put a load in the bed," he observes. "It helps some when the roads are this bad."

"There's a reason for what we saw back there," Beckett declares stubbornly. Her digits pluck idly at her lower lip. "I'm trying to understand what it might be, that's all. Martha associates Castle's music with his innocence. It's a reminder of better times, before she came home too late to stop him from following Laura to Montauk Point. Acting out of character like she did for a chance to hear him play makes sense in that light."

"I suppose."

Kate frowns, shooting a glare over at the driver. "Are you agreeing, or coddling me?"

"A bit of both."

She gapes somewhat and then grumbles, "You're single, aren't you?"

The deputy smirks briefly. "What gave it away?"

"Take some free advice, John. If you're going to put a lady on just to end the conversation, don't admit to it afterwards."

"I assume that's a hypothetical scenario."

"It was right up until you went and did it."

"I meant the part about you being a lady."

Beckett sucks in a gasp of surprise, almost busts out laughing. She contains herself and instead narrows her hazel orbs into blades of feigned indignity.

John doesn't grin, but the corners of his mouth are twitchy from stifling one. "What about you?"

Her eyebrows flip into reversed positions. "Um…I'm engaged, remember? But thanks for asking."

"Not that," he replies dryly.

"Oh," she blurts, somewhat deflated. "Well then thanks for nothing." First Henry and now you. What's a girl gotta do to get a compliment in this town?

The deputy does grin this time, but pushes on, "Don't wiggle out of this. The truth is: you don't need some article or other explanation. No more than I do. You may want one, but the facts are simple enough. Richard is…gifted." Beckett has no intention of arguing that point. "Empathy isn't some pseudoscience that plays to the supernatural. There's nothing mysterious or unexplainable here. It's an exceptional example; I'll grant you that, but it's not an otherworldly one. So what's the harm in accepting it for what it is? Why can't it just be? Rick isn't the next Beethoven or Mozart. We've already heard about how he proved unexceptional in technical ability. It's his capacity for empathy coupled with a powerful imagination: it acts in place of expertise as some sort of, uh, go-between." He frowns, clearly dissatisfied with the conclusion of his observation.

Her companion is an astute man. But she can't help voicing her musings. It is her nature to seek a rational cause and effect. Castle's empathy looks simple enough on paper. It was...until she watched him disassemble Richter into a weeping husk. Kate moistens her lips, voices an alternative version of his conclusion. "His emotional connection to the music inspires his imagination, which propels him into an epiphany. Maybe he was never a prodigy, but his mind seems to operate along a similar path."

John's expression lights up with agreement. "Exactly! So you do get it then."

"Oh I get the effect it produces," she readily concedes. "I'm less sure of its mechanism."

"Does it matter though? The outlandish details to my mind were the reactions from Martha and Richter; equally bizarre, now that I think about it, in that with both of them the prominent emotion was negative. You'd think that his playing would be inspiring to them in turn—a cause for joy."

They each fall quiet, caught and held again by the too fresh memories of recent drama.

"Maybe you've guessed by now, but…I used to sing," Kate offers at length.

John turns away from the road to observe her.

"Not professionally or anything, though I used to imagine trying for that. Uh... My mother was—she was taken from me and my dad fifteen years ago."

"Oh man," he rumbles lowly, facing forward again. "I'm sorry."

"She, uh, she loved to hear me sing." A bittersweet smile comes and goes in a single smooth motion. "Last time I really belted something out for her was when we went Christmas caroling that last year together. She was killed early January. I guess it kinda became one more of those things that hit a little too close to home."

"That's a shame, Kate." He seems to mean it.

Beckett clears her throat roughly and continues, "The point is: I loved singing, but more so because of how Mom enjoyed it. Afterward, I convinced myself that I couldn't sing the same way even if I wanted to. I'd feel guilty having other people hear me, maybe enjoying it. It'd be like re-gifting something special Mom had given with the intent of it only ever belonging to me. Does that make sense?"

"It doesn't actually, no, but I get what you're saying." He smiles somewhat. "As it happens though, I was in Buck's Crab Hut when you and Rick performed for karaoke night a while back. Clearly you got over that guilt."

Kate hums with amusement, but sighs afterward. "It's less now, but still there. Castle has a way of making me forget myself like that sometimes."

"Didn't you drag him onstage?"

The detective quivers lightly, laughing quietly. "He makes me forget about my boundaries. At that point the relationship is admittedly pointed by troublemakers at both ends of the stick."

"Confession is good for the soul."

She laughs again and continues smiling for a good length of time afterwards. It's a little strange given the circumstances, but that makes it more precious too, and she thinks Rick would be pleased to know she was finding some levity. It's his specific intent after all, right? You are the one who asked John to ferry me about. Well-played, babe.

"So what's your point exactly?" John asks. "I lost track of it somewhere."

"Hmm?"

"We were talking about Martha and Richter feeling guilty instead of happy when Rick plays," he clarifies.

"Right. We don't know how Martha would react to hearing him play again though, to be fair. But in regards to Anton…I'm not sure it was his reaction at all: that's what I was working my way towards. That's why I'm a little, uh…unsettled I guess. By comparison, my capability for singing never changed. I know that now. But how, and more importantly, why I sing has. I can discern that difference simply by how people react to it."

John frowns. "I don't understand."

"Hmm. Okay then, forget the comparison. That's tricky to grasp if you haven't performed in front of an audience before. Try it this way instead: whatever the truth may actually be, let's assume for the sake of argument that Anton really is still capable of feelings, and what we saw inside was just him lashing out in response to our aggression. Let's also assume that everything I just said is false. That gives us two unique possibilities."

"Two roads diverging in a yellow wood."

"I'm starting to understand why you and Castle are friends." The man grunts noncommittally, which elicits a smirk from her. "Anyway, using either example there are, logically, two different conclusions we can make about Castle's…ability."

The driver still seems confused, but offers a slow and dubious, "Okay…"

"First possibility: his empathy is a double-edged weapon. In this theory, which Rick would go ape-shit over by the way, Anton felt nothing at all—a pure doll of a man. He used us the way he did simply because it amused him to cause everyone pain. Our behavior was immaterial. It was his final revenge, as Castle described it, and was always intended to be. By that logic though, the emotion we saw him express outside wasn't his at all. What we saw would have been a direct reflection of the music itself, most likely of Rick's feelings about playing again, and Laura specifically." Kate pauses as the words tumble around her heart. Even amidst a purely academic discussion about her partner the emotions rise up, seeking to overwhelm. "Uh," she continues lamely. "Oh. Yes. His empathy. It's been honed over all these years to the point that it's like an arrow shot from a bow." She illustrates by shooting her left arm forward to smack the dashboard with the tips of two fingers. "It sticks right into the audience member, a literal transmission of his emotion into the target."

"Whoa," John murmurs doubtfully. "That's… If that's true we need to sign him up for the X-men."

Kate snorts, rolls her eyes. "Again—this friendship becomes much clearer."

"Honestly, the science there isn't far-fetched at all. Sad music makes us sad—nothing weird about that."

"Not normally, no. The strangeness lies in the degree of the effect it has, which in Richter's case looked pretty goddamn extreme; especially," she adds, stressing the words now, "if we assume he isn't independently capable of emotion. See what I'm getting at? You don't just flip a switch and decide to feel things again. But he reacted as if that's exactly what happened. It was like night and day. That's as good as a supernatural experience in my book, assuming the theory as a whole is true."

The deputy's jaw shifts and flexes as though he were chewing on her proposed scenario. "Agreed," he replies easily enough. "I can see why you'd be distressed and looking for answers: that's a pretty wild theory. And yet…after seeing what I did…" He shifts in his seat again, looking uneasy.

"It's highly unlikely," she offers reassuringly. "Non sequitur even." And yet... Indeed.

"Go on then," John encourages. "What's the second possibility? Assuming that Anton was reacting to our behavior at least in part, and is capable of some measure of remorse…"

"Theory B? Lex parsimoniae."

"Huh?"

"Sorry. I rarely get a chance to say that in conversation. Sounded cool, huh? I'm kind of a smarty-pants, you know." John's massive upper half rocks with a brief, mute chuckle. "It's Occam's Razor. Richter is just human enough that Castle's empathy, though his music, is capable of reminding the killer of what it's like to be fully human again. Frankly, his reaction is all too fitting in this scenario, because I can't imagine a worse kind of torture for the man than to hold normalcy in his hands again only to watch it slowly run right back out though them like so many grains of sand."

John shows no sympathy, but his respectful silence suggests it. At length he offers, "It helps explain the hug. Maybe it will fade, but at least he got to feel it again for a time. At least he knows that he's still capable of feeling it. I imagine that's more than a small relief for a man like that."

"He's capable through Richard," Kate stipulates evenly, and frowns afterward to have used his full name.

"Through Richard, yes." The driver eyes her askance again and his jaws shifts in further contemplation.

"What?"

"I'm curious," he rumbles cautiously. "It's a pretty personal question though."

"You can ask," she replies with a mysterious smirk.

"Do you want to hear Rick play now, after seeing what we've seen? Seems to me like either scenario is equally devastating for people who've maybe...lost touch with some pieces of their hearts."

Beckett frowns and presses back into the seat some while crossing her arms. She doesn't answer. Instead, she eventually says, "Both theories are pretty surreal. Honestly, I don't expect either is true. Hell, maybe it's even a mix of both to some small degree. I'm hoping the Matthews' will offer more information, maybe help clarify the details for us."

John shifts one hand to point a thick digit over the steering wheel, indicating the expansive mansion at the end of the private road they've been following. "Speak of the devil."