A/N: I apologize for the long delay. Please note that I do, in fact, have an endgame in mind for this story, and a way to get there, but I haven't had much time to write lately. But, I figured I would take advantage of a snowy day, and hopefully provide some entertainment to all others who find themselves afflicted. See the first chapter for the disclaimer. I hope you all enjoy this one, and please review. :)

Chapter Ten

Jamie was late.

Flack wasn't sure how much he should read into the situation. Three months into this partnership, though, and Jamie had never been late. From what he'd heard, Jamie'd never been late ever.

So, where was he?

When Jamie finally did come in, Flack smirked, finding himself oddly (and inexplicably) relieved. "Just roll outta bed?" he asked.

Jamie shook his head. "Firearms requalification," he explained.

Flack nodded. "How'd you do?"

Jamie shrugged one shoulder. "Better than Danny."

"Messer or Reagan?"

Jamie smiled, almost proudly. "Both, actually."

Flack chuckled. "Nice to see I've taught you somethin'."

Jamie laughed.

"Well, since you're finally finished shootin' up things, we caught a break in that arson case."

"Which one, the flamethrower or the Molotov cocktail?"

Flack furrowed his brow. "The torched car." He paused a moment before saying, "do we really have three open arsons?"

Jamie scoffed slightly. "Four, if you count the guy they found burned to death next to the Hudson last week."

"I thought that was the flamethrower."

"I thought the flamethrower victim was a woman."

Flack thought for a few minutes, recounting case details in his head. "You're right. Flamethrower was Maria. Hudson was Carl. But who was Molotov?"

Jamie considered it before answering, "Sarah."

"And torched car was Hank," Flack said.

Jamie knit his brow in contemplation. "Does it seem odd to you that we have had four different victims killed by fire over the last five weeks?"

"Yeah." Flack grabbed his coat. "Let's run with it."

Jamie nodded as he followed suit.

"So, we have four vics in five weeks killed by fire," Flack said.

"There can't be that many arsonists out there," Jamie added.

"Is there anything linking these people?"

"Nothing," Mac said. "We have four different methods of delivery, four different locations. Maria was a doctor, Carl was homeless, Hank was a firefighter, and Sara was a bartender."

"Bartender killed by a Molotov?" Jamie asked.

"Carl's home was near the Hudson," Flack added.

"Firefighter killed in a car fire," Mac said.

"But why use a flamethrower on a doctor?" Jamie asked.

"Weapon of convenience?" Flack postulated.

"Who conveniently has a flamethrower lying around?"

"You mean you don't?"

Jamie shook his head at Flack, who smirked.

"If we do have a firebug, we know he won't stop," Mac said, ignoring Flack and Jamie's banter. "He started with torching Hank in his car."

"What if Hank wasn't his first victim?" Jamie questioned.

"We got four other boroughs," Flack said.

"Guy switches delivery systems often, different jurisdictions…"

"We could have a lot more victims out there."

"Detectives from Brooklyn Homicide are sending copies of four odd fire deaths," Flack said. "Get this, all in the last five weeks."

"Homicide in the Bronx is a little too happy to pass theirs off," Jamie said. "They have five."

"Five in Queens, also," Mac added.

"None in Staten Island," Messer said.

"Wanna bet that's where this guy lives?" Jamie asked.

"Too easy," Jo said as she came in. "Why strike that close to home?"

"Just doin' the math here, we have 18 victims in five weeks," Flack pointed out.

"That may or may not be connected. What made you guys look into this?"

"Harvard figured four in Manhattan was odd."

"Won't seem so odd if we find a connection," Jamie said.

"So, the earliest case is Tim from the Bronx," Jamie said as the group poured over the enormous amount of case files. He put her picture on the screen in the front of the timeline.

"Then Tamara from Queens," Mac said.

"Next was Hank from Manhattan," Flack said.

"Then Jose from Brooklyn," Messer said.

"And then the next victim is from the Bronx again," Lindsay said.

"He's systematically going through these four boroughs, but that's not the only pattern," Jo pointed out. "Look at the methods."

"First four vics were all torched in their cars," Hawkes read off.

"Second four were all killed by flamethrowers," Lindsay said.

"Third were all struck with Molotov cocktails," Messer said.

"Fourth, lighter fluid," Mac added.

"And these last two were killed with kerosene," Flack said.

"Each time, he needs to be closer to his victim as he starts the fire," Jo pointed out.

"And he always goes from the Bronx, to Queens, to Manhattan, to Brooklyn," Jamie said.

"We scanned surveillance footage in Manhattan, found a few common people," Adam said. "I'm crossing them with scene surveillance from the other crime scenes."

"We also have the advantage of knowing that the next place he'll strike is Manhattan."

"Manhattan's a big borough," Messer pointed out.

"We get the word out to all five boroughs," Mac said. "Have every cop out there looking for the guys Adam's found so far, as well as anyone who's buying kerosene. Jamie, you might want to brief your father on this."

Jamie nodded.

"Why would someone light someone else on fire?" Jamie asked as he and Flack sat at their desks, monitoring the tip line.

"Why not?" Flack replied. "Works just as good as any other murder weapon."

"But it's much easier to shoot someone, and generally safer to stab someone. So, why fire?"

Flack shrugged. "Shooting leaves behind bullets that can be traced. Stabbing, you risk cutting yourself or getting hurt, which'll leave behind evidence. Fire, however, generally destroys evidence."

"But not all evidence."

"Trace and DNA would be gone, though. Except for trace from the fire."

"Because fire creates its own evidence."

Flack nodded. "Fire's unpredictable. Maybe we oughta canvass clinics and hospitals for burn patients, coinciding with the dates he switched to being up close and personal. When was that?"

Jamie looked at the timeline. "About six days ago."

"So, we send the mugs of the lookee-loos to docs at clinics and hospitals in all five boroughs."

"Or maybe just Staten Island," Jamie said. "Wouldn't you go to your home doc if you just committed homicide?"

"Hmm, not sure," Flack countered with a grin. "I don't often commit homicide."

"Really? I thought that was your weekend gig."

Flack half-shrugged. "Gave it up for the holidays."

Jamie laughed.