Poison Pen

Chapter 3

"The N.Y.P.D. does occasionally enlist the aid of consultants," Kate admits, "but the decision to take one on is above my pay grade. I'll have to run it past my captain, and until I can do that, I'll have uniformed officers take you home and put a watch on your place. Except that I have no idea where you live. It could be outside the jurisdiction of this precinct."

"Knowledge of the location of my residence is fairly tightly held, which is why most of my correspondence goes to Paula. I keep a low personal profile for my daughter's sake, more than my own. However," Rick confides, "my home is not only within your jurisdiction; it's within walking distance."

"You're not walking anywhere at 1 a.m., Mr. Castle," Kate declares. "Take the ride. I'll be in touch."

Rick tips an imaginary hat. "I look forward to it, Detective Beckett."

Captain Roy Montgomery runs his hand over his too rapidly balding pate. "Are you telling me that Richard Castle wants in on your case?"

Clasping her hands behind her back, Kate twists her fingers. "Yes, Sir. He has already been helpful in providing a possible direction for our search for Connor O'Donnell's killer. And if he is the killer's next target, we'll be able to keep a watch on him."

"Unless he gets killed while he's playing detective with you. That could be a PR nightmare. On the other hand, the commissioner put out a directive for us to get any positive press that we can for the department. There have been some incidents lately that have had the opposite effect — nothing involving cops from the 12th, but in the eyes of the public, we all get tarred with the same brush. Kimmel likes having authors on. Maybe Castle can plug us next time he makes an appearance. All right, Beckett, Castle can help with the case, just make sure he doesn't get hurt or pissed off. If he talks about us on TV, he'd better say something nice or the commissioner will have both our asses."

"Yes, Sir. I'll give Castle a call and have the unit guarding him to bring him in."

As his electric razor buzzes away his morning stubble, Castle examines his face in his bathroom mirror. His lack of sleep shows, but he's not about to climb back into his bed. After working as hard as he did to solicit Detective Beckett's invitation, he's not about to mess up his chances to spend some time with her. He's also serious about wanting to help her solve the case. The last thing he needs is some crazy wanting to bury him alongside the late lamented Derrick Storm.

Keeping his ass intact aside, he hasn't been drawn to a woman the way he's attracted to Beckett since the three years he spent with Kyra Blaine while they were in college. He can blame that obsession on rampant hormones, but he's not a kid anymore. Whatever he feels for Kate is adult in every way, and other than ensuring they're in proximity, he has no plan for what to do about it. He rechecks the mirror. Maybe eye drops will help, that and a large mug of coffee that's a lot better than the battery acid at the precinct.

Castle studies each word of copies of the excoriating letters that he, Connor O'Donnell, and the killer's first known victim, Salmon Ivanovich, received. "This is one angry guy, Detective Beckett."

"He did kill two people," Kate points out.

"True," Castle agrees, "but I'd previously pegged him more as jealous. Ivanovich, O'Donnell and I, got something that he wanted. But there's more than than a green-eyed monster here. Writers choose their words very carefully. Just picking something from a list in a Thesaurus won't do it. A laugh isn't the same as a giggle, which is distinct from a guffaw. The emotional weights of synonyms differ. With our murderer, almost every choice indicates controlled rage. He kills with a careful plan. Even his weapon selection would be a statement of dominance over his impulses. He's also exerting superiority over his victims."

"Assuming that you're right, Castle, how does that get us any closer to identifying him?" Kate questions. "The letters all had different postmarks, phony back addresses, and no fingerprints. So far, the lab hasn't found any DNA either."

"Those are all indications of his drive for control," Castle insists. "We're looking for long words instead of short ones because they tend to have more precise meanings. Whatever he says will feature as little ambiguity as possible. If he has books out, they are probably self-published and written the same way. Along with internet postings by the killer, we can look for reviews that cite that type of anal-retentiveness. Those could lead us to the author."

Waving a file, Ryan joins Kate and Rick in the conference room. "We got the lab results on the poison. It's a blarina toxin."

"Shrew venom?" Castle asks.

"That's right, Mr. Castle," Ryan confirms. "The lab boys have never seen it before, but they matched it to a structure isolated by Japanese researchers. How did you know?"

"My daughter, Alexis, did a paper on poisonous mammals. I helped her with her research. It fits," Rick concludes, turning to Kate. "One of the synonyms for shrew is fury, which in turn can be defined as an avenging spirit. It's a play on words to demonstrate the killer's language supremacy."

"I've got another description for what he did," Kate announces triumphantly — "hubris. His efforts at showing the world how clever he is gave us a trail to follow. There can't be that many places to get shrew venom. If we trace down the sources and their customers, we may uncover a suspect. Ryan, you and Esposito get started on that, Castle and I will go at it from the angle of the killer's writing. Sooner or later, what we find will overlap."

A messenger knocks on the doorframe of the conference room. "I have a package for a Detective Beckett, homicide dept, 12th Precinct."

"I didn't order anything," Kate protests, "and I don't have things delivered here."

Ryan reaches for his phone. "We should call the bomb squad."

Castle frantically waves both hands in the air "Whoa! It's not a bomb. I sent it. It's a new coffee maker for the break room. With the sludge I've had here, I figured you need one. It also makes espresso and lattes. It'll save you trips to the Java Hut."

Ryan claps his hands together. "Great! Thanks, Castle. I'll help you set it up."

"Ryan, shrew venom," Kate interjects.

Castle takes the heavy carton from the delivery man. "That's all right. I have one like it at my loft. I know how to set it up. Be right back. And Beckett, try the Sharper Point chatroom. It's an online writer's exchange where our killer might hang out.

"That was nice of him," Ryan comments with a knowing look at Kate as Castle takes off for the break room. At Beckett's sharp stare, Ryan heads for the bullpen. "Right. Blarina toxin."

Kate flips open her laptop and types "sharper point chatroom" into Google. As she scrolls through snarky commentary, Kate has a feeling that Castle might be right about it as a possible posting site for the killer. She's also hoping that he hurries up with the coffee machine. As sleep-deprived as she is, she can use an espresso — a triple espresso. She suspects Castle can too.