Shared Obsession Chapter 143
"We've run through all the conventional crypto. We can't crack it," Avery announces in disgust.
"Which means what?" Castle queries.
"There's either a reference key we don't have or the code itself is just a random string of numbers," Avery explains.
Shaw scowls, shaking her head. "It's not random. He bought another man's finger so he could leave a message that would lead us directly to the code. That's how he taunts Nikki. He's saying, 'Are you clever enough to solve my riddle?' So whatever his reference key is, he thinks we can find it."
Kate starts pacing in front of the smart board. "Those numbers could mean anything."
"But he's using "Heat Wave' as his playbook to Nikki Heat," Castle asserts. "Beckett, maybe it's kind of like the orders that went out in the Manna Bibles, only with numbers. The left hand column is less than 300. The right hand column is no more than 260."
"And using the key, the combination of the two should yield a word," Shaw realizes.
"Words. The key has got to be 'Heat Wave,'" Castle asserts. "The typeset manuscript was usually 300 words a page and not counting the flyleaf, publisher's inserts and acknowledgments, which have Roman numerals, 'Heat Wave' is 260 pages." They all reach for copies of "Heat Wave," stacked on a table nearby. "So column one is a page number and column two…."
"Counting backward from the bottom," Kate puts in, pointing at a rendering of Salt's finger wrapping.
"Seventy-nine," Castle continues. "Second column is a word, um, 32, 33, 'I.'"
Shaw picks up the thread. "126, 80, 'will.'"
Color drains from Kate's face. "145, 204, 'kill.'
Castle swallows. "I will kill…."
"Hold on," Avery interjects. "Uploading the text now."
The computer beeps as the completed message appears on the massive screen. "I will kill someone else before midnight unless you stop me," Castle reads.
Kate glances down at the men's watch on her wrist. "Midnight, that's eight hours from now."
Castle hands Kate a mug of coffee as she perches on a desk in front of her dry-erase board. "Kicking it old school?"
She takes the mug, letting the warmth seep up through her fingers. "The whiteboard's always worked for me."
"I know," Castle acknowledges. "Much as I love the fancy toys, we wasted a lot of time letting them try to do the work for us decoding that message. The connection to 'Heat Wave' is clear, or Agent Shaw never would have handed out all those copies in the first place. We could have been hours ahead if we'd started there. So what are you working on now?"
"I've been going over subway routes, trying to see if I can trace a pattern from Grand Central to the carousel to the next location. So far, nothing definitive."
"He might not take the subway," Castle considers. "He had $5,000, which I would assume was in cash, to buy Salt's finger and cooperation. A cab would be too easily traceable, so he might have the means to own a car. But maybe there's something about how he chooses his victims. First a man and then a woman."
Kate slams her heel against the side of the desk. "A lawyer and a dog walker? Let's face it, there's no pattern there. There is no way to predict where he's gonna go next and it's already nine o'clock. We're almost out of time. And every murder he commits in the name of Nikki Heat…."
"Is not your fault. He's a psychopath, acting out of his madness. Agent Shaw said if he hadn't invested in Nikki Heat, he would have picked someone else. And if anyone is to blame, it's me, not you, for writing the damn book."
"You're not to blame."
"Then neither are you. And we've still got three hours."
"Beckett! We've got something!" Avery calls from the war room. Kate and Castle rush in. "Lab results came back on that bandage," Avery explains. "It tested positive for formaldehyde, methanol, and ethanol."
"Embalming fluid," Castle exclaims simultaneously with Agent Shaw.
"If I remember my AP chemistry," Castle continues, "methanol and ethanol are both very volatile. Our killer must have really loaded that bandage up for there to be residue after being on Salt's finger all that time. This must have been what he wanted Beckett to discover."
"The lab found traces of formaldehyde at Grand Central and ethanol at the carousel," Shaw adds.
Castle and Kate look at each other. "That's the pattern!"
"The killer could work at a mortuary," Castle proposes, "or if he has money, own one."
"Or he could be a hospital employee or work at a morgue," Kate offers.
"Mr. Castle's theory is more likely," Shaw decides. "Bring up all the mortuaries in the city."
"We've got over a thousand mortuaries in the metro area," Avery reports. "We can't hit all those before midnight."
"Can you cross reference mortuary experience with criminal records?" Castle asks.
Avery's fingers fly over a keyboard. "I've got six names."
"Mobilize the troops," Shaw orders. "I want every one of those guys in custody before midnight." She throws a glance at Beckett. "I see what you mean about him being helpful."
"Any of these undertakers look good for it?" Montgomery asks as he, Kate, and Castle watch the questioning in the box.
Castle sighs. "They all say the same thing. 'We work with dead bodies all day. We don't need to make more.'"
"He baited us," Kate hisses, "just like with the fingerprints. We're wasting our time."
Ryan trots up. "He's on the phone. He's asking for Nikki Heat."
Beckett stalks out to the bullpen toward the phone, with Castle at her elbow.
"We're tracing the call," Shaw tells her.
Kate puts the call on speaker. "Hello."
She immediately recognizes the voice. "Nikki, you were supposed to stop me. I wanted you to stop me."
"Tell me where you are," Kate demands.
"Will you come alone?" her taunter asks.
Kate glances at Shaw, who nods, garnering a distressed look from Castle. "Yes, just you and me. We can figure this out. I can help you. You just need to trust me."
The killer's contempt carries through the room. "Tell me. How does it feel to fail?"
"Got his location," Avery mouths.
The sound of screeching tires echoes off the concrete walls of a parking garage. "Check the stairs," Shaw commands as agents rush out of their vehicles. "I want a unit on the roof. I want eyes on every inch of this structure."
Kate whirls around, surveying the open space. "He was just here. That body can't be too far."
"Over here!" Ryan yells. "A lot of blood. A woman's shoe. Got a broken heel."
Shaw studies the scene. "Strands of hair, too. She put up a fight."
Kate points at the floor. "Four shell casings. There's no way she would have survived without medical attention."
"Where's the body?" Castle asks. "Before, he left his victims where he killed them."
"And he killed in famous places with lots of foot traffic," Shaw adds. "He's changed his MO."
Castle stares into the emptiness. "Which makes him more unpredictable, more dangerous."
"Structure's clear. No body." Avery reports.
"Then where did he put her?" Shaw wonders.
Kate crouches near a line of red drops. "He put her in his trunk. The blood trail ends here."
"So he waited, probably left his car idling, which tells us he used one," Castle figures. "Then he takes down his victim, shoves her in the trunk, and drives away."
"Get the parking attendant to give us a list of all the vehicles that went through here and get the video," Shaw instructs Avery.
"Do you think he drove his own car?" Castle asks Shaw.
"No, but if he stole one tonight, he might not have had time to switch the plates," she considers. "We'll put out an APB."
"I'll get my guys to get a roster of everyone who had monthlies on this floor," Kate tells Shaw.
"My guys are already on it, and I've got way more people than you do.," Shaw replies. "Your captain told me he has a unit on your apartment. Go home. Get some rest."
"It's not necess…." Kate starts to protest.
"No argument," Shaw insists. "You're no good to me if you're burned out."
Castle watches Kate reluctantly climb into her unit. "Pancakes," he murmurs to himself, "she's going to need pancakes."
